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Clinical Reference
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Interpretation guide
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Restrictive Cardiomyopathy
Cardiovascular Presentations
Abdominal aortic aneurysm
Acute coronary syndrome (NSTEMI)
Acute coronary syndrome (STEMI)
Acute decompensated heart failure
Acute limb ischemia
Acute mesenteric ischemia
Aortic dissection
Aortic stenosis
Atrial fibrillation and flutter
Bradyarrhythmia and heart block
Cardiac arrest
Deep vein thrombosis
Myocarditis
Pericarditis
Pulmonary embolism
Stable angina
Superficial thrombophlebitis
Superior vena cava syndrome
Supraventricular tachycardia
Syncope (cardiogenic)
Unstable angina
Ventricular tachycardia
Respiratory Presentations
Acute bronchitis
Acute respiratory failure
Aspiration pneumonia
Asthma exacerbation
Bronchiolitis
Community-acquired pneumonia
COVID-19 pneumonia
COPD exacerbation
Croup
Croup (laryngotracheobronchitis)
Epiglottitis
Hemothorax
Hospital-acquired pneumonia
Pleural effusion
Pneumothorax (traumatic)
Pulmonary contusion
Spontaneous pneumothorax
Neurological Presentations
Bell's palsy
Benign paroxysmal positional vertigo
Brain abscess
Cauda equina syndrome
Cervical radiculopathy
Concussion (mild traumatic brain injury)
Encephalitis
Guillain-Barré syndrome
Hemorrhagic stroke (intracerebral)
Ischemic stroke
Lumbar radiculopathy
Malignant spinal cord compression
Migraine
Peripheral neuropathy (acute)
Retropharyngeal abscess
Schizophrenia (acute exacerbation)
Seizure (breakthrough:known epilepsy)
Seizure (first-time)
Spinal cord injury
Status epilepticus
Subarachnoid hemorrhage
Tension headache
Transient ischemic attack
Traumatic brain injury (moderate-severe)
Vestibular neuritis
Viral meningitis
Gastrointestinal Presentations
Acute appendicitis
Acute cholecystitis
Acute diverticulitis
Acute pancreatitis
Anal fissure
Choledocholithiasis and cholangitis
Clostridioides difficile colitis
Gastritis
Gastroenteritis (viral and bacterial)
Gastroesophageal reflux disease
Incarcerated or strangulated hernia
Inflammatory bowel disease flare
Large bowel obstruction
Lower GI hemorrhage
Peptic ulcer disease
Perforated viscus
Small bowel obstruction
Upper GI hemorrhage
Genitourinary and Reproductive Presentations
Acute prostatitis
Acute urinary retention
Ectopic pregnancy
Epididymitis
Orchitis
Ovarian torsion
Paraphimosis
Pelvic inflammatory disease
Priapism
Pyelonephritis
Renal laceration
Ruptured ovarian cyst
Testicular torsion
Tubo-ovarian abscess
Urinary tract infection (uncomplicated)
Urolithiasis (renal colic)
Vaginal bleeding (non-pregnant)
Infectious Disease Presentations
Acute sinusitis
Acute tonsillitis
Acute upper respiratory infection
Animal bite
Bacterial meningitis
Cellulitis
Conjunctivitis (bacterial)
Dental abscess
Endocarditis
Febrile neutropenia
Fournier gangrene
Hand-foot-mouth disease
Hepatitis (acute)
Herpes zoster
HIV-related illness
Human bite
Impetigo
Infected diabetic foot ulcer
Infectious mononucleosis
Influenza
Necrotizing fasciitis
Osteomyelitis
Otitis externa
Parasitic infection
Periorbital cellulitis
Peritonsillar abscess
Scabies
Sepsis
Septic arthritis
Spontaneous bacterial peritonitis
Tick-borne illness (Lyme disease)
Tinea infection
Tuberculosis
Viral exanthem
Wound infection
Trauma Presentations
Achilles tendon rupture
ACL and mceniscus tear
Ankle fracture
Ankle sprain
Burn
Calcaneus fracture
Cervical spine fracture
Clavicle fracture
Dental avulsion
Distal radius fracture
Drowning
Elbow fracture and dislocation
Electrical injury
Facial bone fracture
Facial laceration
Femur fracture
Fingertip amputation
Forearm fracture (radius and ulna)
Frostbite
Hand:finger laceration
Heat exhaustion
Heat stroke
Hip fracture
Humeral shaft fracture
Knee dislocation
Knee sprain
Lightning injury
Mandible fracture
Metacarpal fracture
Metatarsal fracture
Muscle strain
Nasal fracture
Non-accidental trauma
Orbital fracture
Patella fracture
Phalanx fracture (finger)
Proximal humerus fracture
Pulmonary contusion
Rib fracture
Rotator cuff tear (acute traumatic)
Scalp laceration
Scaphoid fracture
Shoulder dislocation
Skull fracture
Splenic laceration
Sternal fracture
Supracondylar pediatric fracture
Tendon laceration (hand:wrist)
Thoracic and lumbar spine fracture
Tibia:fibula fracture
Tibial plateau fracture
Toe fracture
Traumatic epistaxis
Traumatic hyphema
Toxicologic Presentations
Acetaminophen toxicity
Alcohol intoxication
Alcohol withdrawal
Anticholinergic toxicity
Anticoagulant overdose
Benzodiazepine overdose
Benzodiazepine:sedative overdose
Beta-blocker and calcium channel blocker toxicity
Carbon monoxide poisoning
Caustic ingestion
Digoxin toxicity
Drug eruption
Foreign body ingestion
Opioid intoxication
Opioid overdose
Opioid withdrawal
Organophosphate
Salicylate toxicity
Serotonin syndrome
Stimulant intoxication (cocaine, methamphetamine)
Tricyclic antidepressant overdose
Psychiatric Presentations
Acute anxiety
Acute psychosis
Agitation:behavioral emergency
Bipolar disorder
Conversion disorder
Major depressive episode
Neuroleptic malignant syndrome
Suicidal ideation and attempt
Musculoskeletal and Rheumatologic Presentations
Acute low back pain (mechanical)
Bursitis
Cervical radiculopathy
Costochondritis
Gout (acute)
Lumbar radiculopathy
Pseudogout
Tendinitis
Dermatology Presentations
Acute eczema (Eczema acute flare)
Allergic contact dermatitis
Erythema multiforme
Henoch-Schönlein purpura
Pressure injury
Psoriasis (acute flare)
Stevens-Johnson syndrome
Toxic epidermal necrolysis
Urticaria (acute)
Environmental and Exposure Presentations
Envenomation (snake, spider, insect)
High-altitude illness
Hypothermia
Hematologic and Oncologic Presentations
Acute chest syndrome
Coagulopathy
Hyperviscosity syndrome
Sickle cell crisis (vaso-occlusive)
Symptomatic anemia
Thrombocytopenia (severe)
Tumor lysis syndrome
Pediatric-Specific Presentations
Bronchiolitis
Croup
Emergency delivery
Febrile seizure
Kawasaki disease
Neonatal jaundice
Neonatal sepsis
Nursemaid's elbow
Pediatric fever 0 to 28 days
Pediatric fever 29 to 60 days
Pediatric fever 61 to 90 days
Pyloric stenosis
Slipped capital femoral epiphysis
Intussusception
Endocrine and Metabolic Presentations
Adrenal crisis
Diabetic ketoacidosis
Hypercalcemia
Hyperosmolar hyperglycemic state
Hypertensive emergency
Hypertensive urgency
Hypoglycemia
Myasthenia gravis crisis
Myxedema coma
Severe hyperkalemia
Severe hyponatremia
Thyroid storm
ENT and Maxillofacial Presentations
Acute laryngitis
Acute otitis media
Acute pharyngitis
Cerumen impaction
Epistaxis (anterior)
Nasal foreign body
Otitis externa
Tympanic membrane perforation
Ophthalmologic Presentations
Acute angle-closure glaucoma
Central retinal artery occlusion
Chemical eye injury
Corneal abrasion
Corneal ulcer
Globe rupture
Ocular foreign body
Orbital cellulitis
Retinal detachment
Obstetric Presentations
Hyperemesis gravidarum
Painful vaginal bleeding in pregnancy
Placenta previa
Placental abruption
Preeclampsia:eclampsia
Preterm labor
Threatened:inevitable:incomplete abortion
Systemic and Miscellaneous Presentations
Anaphylaxis
Angioedema
Cannabis-induced hyperemesis
Restrictive Cardiomyopathy
POCUS
Procedures
Calculators
Resuscitation
ECG Guide
Back
Clinical Assessment Checklist
Browse categories and answer follow-up questions to refine your symptom profile.
Approach to the Critical Patient
Immediate priorities
Hemodynamic threat recognition
▶
Low cardiac output state
▶
Cool extremities
Altered mental status
Hypotension SBP < 90 mmHg
Acute decompensated heart failure
▶
Severe dyspnea at rest
SpO2 < 90% on room air
If cardiogenic shock, urgent advanced heart failure or cardiac surgery consult
▶
Bridge to transplantation planning
Mechanical circulatory support consideration
Arrhythmia and conduction threat
▶
Atrial fibrillation with rapid ventricular response
▶
Hemodynamic instability threshold for cardioversion
Rate control preferred when stable
High-degree AV block
▶
Suggests infiltrative process (amyloidosis, sarcoidosis)
Transcutaneous pacing readiness
Ventricular arrhythmia
▶
Defibrillator availability
Antiarrhythmic selection based on underlying etiology
Thromboembolic threat
▶
Stroke or peripheral embolism at presentation
▶
CT head without contrast for acute stroke
Anticoagulation status review
Massive pulmonary embolism
▶
Differentiate from primary RCM hemodynamics
Monitoring and targets
Monitoring bundle
▶
Continuous cardiac monitoring
▶
Rhythm strip assessment
PR and QRS interval tracking for infiltrative disease
Continuous pulse oximetry
▶
SpO2 target 92 to 96%
Escalate oxygen delivery if below target
Blood pressure monitoring
▶
Hypotension risk with diuresis in noncompliant ventricle
MAP target >= 60 mmHg
Diuresis safety targets
▶
Urine output monitoring
▶
Target 0.5 to 1 mL/kg/hour
Overdiuresis causes prerenal azotemia and low output
Daily weights
▶
0.5 to 1 kg net negative per day target
Creatinine trend monitoring
Immediate consults
Consultation triggers
▶
Advanced heart failure or transplant cardiology
▶
All confirmed or strongly suspected RCM
Transplant candidacy evaluation early
Hematology
▶
Suspected AL amyloidosis or plasma cell dyscrasia
Chemotherapy coordination
Electrophysiology
▶
New high-degree AV block
Ventricular arrhythmia in sarcoid or amyloid RCM
History
Presentation pattern
Cardinal symptoms
▶
Dyspnea on exertion
▶
Most common presenting symptom
Impaired ventricular filling at higher heart rates
Fatigue and exercise intolerance
▶
Fixed or reduced stroke volume
Inability to augment cardiac output with demand
Lower extremity edema
▶
Bilateral, progressive
May reach thigh level in severe cases
Abdominal distension
▶
Ascites from elevated right heart pressures
Early satiety from hepatomegaly and bowel edema
Additional symptoms
▶
Orthopnea and paroxysmal nocturnal dyspnea
▶
Pulmonary venous congestion
Increased venous return in recumbent position
Palpitations
▶
Atrial fibrillation very common
Ventricular arrhythmia in infiltrative disease
Syncope or presyncope
▶
Arrhythmia or severely impaired cardiac output
High-risk alarm feature
Risk factors
Infiltrative causes
▶
Amyloidosis risk factors
▶
Age > 60 years for ATTR
African American descent (Val122Ile TTR variant)
Monoclonal gammopathy (AL amyloidosis)
Sarcoidosis risk factors
▶
Young to middle-aged adults
African American predilection
Known pulmonary or systemic sarcoidosis
Storage and metabolic causes
▶
Hemochromatosis
▶
Hereditary (HFE gene mutations)
Transfusion-related iron overload
Fabry disease
▶
X-linked lysosomal storage disorder
Young men with renal and neurologic features
Iatrogenic and environmental causes
▶
Chest radiation therapy
▶
Hodgkin lymphoma history
Breast cancer radiotherapy
Anthracycline chemotherapy
▶
Cumulative dose-dependent injury
Doxorubicin most common offender
Endomyocardial fibrosis
▶
Tropical regions (sub-Saharan Africa, South America)
Eosinophilic infiltration mechanism
Clues to etiology
Amyloidosis-specific clues
▶
Bilateral carpal tunnel syndrome
▶
Especially bilateral or recurrent carpal tunnel
ATTR amyloid deposits in tenosynovium
Lumbar spinal stenosis
▶
Multiple orthopedic surgeries without resolution
ATTR soft-tissue amyloid
Biceps tendon rupture
▶
Spontaneous or minimal-trauma rupture
Amyloid-laden tendon
Peripheral neuropathy or autonomic dysfunction
▶
Variant ATTR or AL amyloidosis
Postural hypotension and diarrhea
Periorbital purpura
▶
Pathognomonic for AL amyloidosis
Vascular fragility from amyloid deposition
Macroglossia
▶
AL amyloidosis pattern
Impaired speech and swallowing
Sarcoidosis clues
▶
Skin rash (erythema nodosum, lupus pernio)
Bilateral hilar lymphadenopathy on prior imaging
Uveitis or anterior chamber inflammation
Family history
▶
Cardiomyopathy, sudden cardiac death, heart failure
▶
Genetic RCM shares mutations with HCM (MYH7, TNNI3, TNNT2, ACTC1)
Up to 75% of idiopathic RCM has identifiable genetic cause
Hereditary ATTR
▶
Neuropathy and cardiac disease in first-degree relatives
Vitreous opacities in some hereditary variants
Past medical history
Key comorbidities
▶
Known amyloidosis, sarcoidosis, hemochromatosis, Fabry disease
Malignancy with chest radiation or anthracycline exposure
Chronic inflammatory conditions (rheumatoid arthritis, IBD)
▶
AA amyloidosis risk from sustained inflammation
Prior thromboembolic events
Chronic kidney disease complicating management
Pericardial history
▶
Prior pericarditis or cardiac surgery
▶
Raises constrictive pericarditis as mimic
Critical differential before proceeding to RCM diagnosis
Physical Exam
Vitals and general
Stability assessment
▶
Heart rate
▶
Tachycardia common from low output state
Rate dependence on heart rate for cardiac output
Blood pressure
▶
Low-normal or hypotensive
Narrow pulse pressure suggests reduced stroke volume
Respiratory rate
▶
Elevated with pulmonary congestion
>= 24 per minute as severity marker
Oxygen saturation
▶
Room air SpO2 below 92% as admission trigger
General appearance
▶
Cachexia and muscle wasting
▶
Chronic low-output state and poor nutrition
Cardiac cachexia adverse prognostic marker
Respiratory distress at rest
▶
Orthopnea position preference
Accessory muscle use with decompensation
Cardiovascular exam
Jugular venous pressure
▶
Elevated JVP
▶
Prominent x and y descents
Y descent rapid in restrictive physiology
Kussmaul's sign
▶
JVP rises with inspiration
More classic for constriction but may occur in RCM
Precordial exam
▶
Apical impulse
▶
Usually palpable
Mildly displaced or non-displaced (no LV dilation)
Heart sounds
▶
Normal S1 and S2
S4 gallop typical (stiff noncompliant ventricle)
S3 may also be present in severe diastolic failure
Murmurs
▶
Mitral regurgitation frequently present
Tricuspid regurgitation from right-sided congestion
Peripheral and abdominal exam
Right heart congestion signs
▶
Hepatomegaly
▶
Pulsatile with tricuspid regurgitation
Right upper quadrant tenderness
Ascites
▶
Fluid wave on percussion
Shifting dullness
Peripheral edema
▶
Bilateral pitting edema of lower extremities
May extend to thighs, sacrum, and scrotum
Pulmonary congestion signs
▶
Bibasilar crackles
▶
Fine crackles at bases
Pleural effusion dullness to percussion
Extra-cardiac amyloid signs
▶
Macroglossia
Periorbital purpura
Peripheral neuropathy on neurologic screen
Skin thickening in scleroderma-related RCM
PITFALLS
Missed diagnosis pitfalls
▶
RCM mistaken for constrictive pericarditis
▶
Both present with elevated JVP and low output
Constriction is potentially curable; RCM is not
Tissue Doppler e' velocity is key differentiator
Amyloidosis unrecognized
▶
Non-specific heart failure presentation
Classic skin and soft-tissue clues often overlooked
RCM in children misattributed to viral myocarditis
▶
Genetic testing essential in pediatric cases
Two-year survival < 50% in children without transplant
Differential Diagnosis
Critical mimics
Constrictive pericarditis
▶
ICD-10 I31.1
Potentially curable with pericardiectomy
Distinguishing features favoring constriction
▶
Tissue Doppler e' > 8 cm/s (reduced in RCM < 8 cm/s)
Respirophasic septal shift (septal bounce) present
Discordant ventricular pressure changes on catheterization
Pericardial thickening > 4 mm on CT or MRI
Features favoring RCM
▶
Concordant ventricular pressure changes
Markedly reduced e' velocity
Tissue characterization on CMR (fibrosis, infiltration)
Cardiac tamponade
▶
ICD-10 I31.4
Pericardial effusion with hemodynamic compromise
Equalization of pressures and pulsus paradoxus
Hypertrophic cardiomyopathy with restrictive physiology
▶
ICD-10 I42.2
Genetic overlap (MYH7, TNNI3 shared mutations)
LV wall thickness predominant in HCM
Cardiac causes of similar presentation
Hypertensive heart disease with HFpEF
▶
ICD-10 I11.0
Chronic hypertension history
LV hypertrophy without infiltrative pattern
Valvular inlet obstruction
▶
Mitral stenosis (ICD-10 I05.0)
Tricuspid stenosis
Must be excluded by echocardiography
Right heart failure from pulmonary hypertension
▶
ICD-10 I27.0
Elevated RVSP on echo
RV dilation without biventricular diastolic restriction
Ischemic cardiomyopathy
▶
ICD-10 I25.5
Wall motion abnormalities
Coronary artery disease history
Non-cardiac mimics
Hepatic cirrhosis with ascites
▶
ICD-10 K74.6
Liver disease stigmata
Normal cardiac filling pressures
Nephrotic syndrome with edema
▶
ICD-10 N04.9
Proteinuria on urinalysis
Hypoalbuminemia
Laboratory Tests
Core workup
Cardiac biomarkers
▶
BNP or NT-proBNP
▶
Significantly elevated in RCM
BNP > 600 pg/mL typical (median ~124 pg/mL in constrictive pericarditis)
Helps differentiate RCM from constriction though overlap exists
Troponin
▶
May be chronically elevated in infiltrative disease
Amyloidosis and sarcoidosis myocardial injury
Complete blood count
▶
Anemia as heart failure exacerbant
Eosinophilia suggests hypereosinophilic syndrome
Comprehensive metabolic panel
▶
Renal function for diuretic management
Liver function from hepatic congestion
Electrolytes (sodium, potassium, magnesium)
Etiology-specific labs
Amyloidosis workup
▶
Serum protein electrophoresis (SPEP) with immunofixation
▶
Monoclonal protein detection for AL amyloidosis
Sensitivity for M-protein increased with immunofixation
Urine protein electrophoresis (UPEP) with immunofixation
▶
Bence-Jones protein detection
Complements SPEP for complete AL screening
Free light chains (serum)
▶
Kappa/lambda ratio
Abnormal ratio suggests AL amyloidosis
TTR gene sequencing
▶
Hereditary ATTR variant identification
Val122Ile for African American ATTR-CM
Over 130 pathogenic TTR variants identified
Hemochromatosis
▶
Serum ferritin
▶
Markedly elevated in iron overload
Acute-phase reactant limitation
Transferrin saturation
▶
> 45% suggestive of iron overload
> 60% with ferritin elevation highly specific
HFE gene mutation analysis
▶
C282Y and H63D mutations
Sarcoidosis
▶
ACE level
▶
Elevated in active sarcoidosis
Sensitivity 50 to 60%, specificity moderate
Calcium (hypercalcemia in sarcoidosis)
Fabry disease
▶
Alpha-galactosidase A enzyme activity
▶
Reduced in affected males
Female carriers may have normal activity
GLA gene sequencing for equivocal cases
Genetic testing
▶
Sarcomeric gene panel
▶
Yield up to 60% in familial RCM
Overlap with HCM/DCM gene panels
MYH7, TNNI3, TNNT2, ACTC1 most common
Coagulation and hematology
Coagulation studies
▶
INR baseline before anticoagulation
Prothrombin time and aPTT
Thyroid function
▶
TSH to exclude thyroid disease contributing to heart failure
Urine analysis
▶
Proteinuria screen for nephrotic syndrome mimic
Hematuria in Fabry disease
Diagnostic Tests
Scoring Systems
Heart failure staging tools
▶
NYHA Functional Classification
▶
Class I: No symptoms with ordinary activity
Class II: Slight limitation with ordinary activity
Class III: Marked limitation with less than ordinary activity
Class IV: Symptoms at rest
Important for transplant listing criteria (Class III-IV)
ACC/AHA Heart Failure Staging
▶
Stage A: Risk factors without structural disease
Stage B: Structural disease without symptoms
Stage C: Structural disease with symptoms
Stage D: Refractory heart failure
Transplant risk tools
▶
SHFM (Seattle Heart Failure Model)
▶
Estimated 1, 2, 5-year survival
Guides transplant listing urgency
HFSS (Heart Failure Survival Score)
▶
Multivariate risk stratification
LVEF, heart rate, IVCD, peak VO2, sodium, ischemia
Differentiating RCM from constrictive pericarditis
▶
No validated single scoring tool
▶
Multi-modality assessment required
Invasive hemodynamics as gold standard when noninvasive inconclusive
MRI
Cardiac MRI (CMR) indications
▶
Tissue characterization
▶
First-line for identifying underlying etiology
Late gadolinium enhancement (LGE) pattern critical
Amyloidosis pattern on CMR
▶
Diffuse subendocardial or transmural LGE
Difficulty nulling myocardium (elevated T1)
Native T1 mapping elevated (> 1050 ms at 1.5T typical)
Extracellular volume fraction > 40% diagnostic for amyloid
Sarcoidosis pattern on CMR
▶
Patchy mid-wall or epicardial LGE
Predilection for basal septum and lateral wall
Active inflammation on T2 mapping
Hemochromatosis pattern on CMR
▶
Reduced T2* signal from iron deposition
T2* < 20 ms indicates significant iron loading
T1 mapping also reduced
Idiopathic or sarcomeric RCM
▶
May show patchy fibrosis or no LGE
Biatrial enlargement prominent
Normal LV wall thickness and volume
CMR operational considerations
▶
Gadolinium contraindicated in severe renal impairment (eGFR < 30)
▶
Non-contrast T1/T2 mapping still informative
Pacemaker and ICD compatibility assessment required
CT
Cardiac CT indications
▶
Pericardial assessment
▶
Pericardial thickness > 4 mm supports constrictive pericarditis
Pericardial calcification in chronic constriction
Critical to differentiate from RCM before management
Coronary anatomy
▶
Exclude obstructive coronary disease
Non-invasive alternative to coronary angiography in low-to-intermediate risk
Structural assessment
▶
Biventricular morphology
Biatrial size quantification
Bone scintigraphy (nuclear imaging)
▶
Tc-99m PYP/DPD/HMDP scintigraphy
▶
High sensitivity and specificity for ATTR cardiac amyloidosis
Grade 2 or 3 uptake highly specific when monoclonal protein absent
Must exclude AL amyloidosis (SPEP/UPEP/FLC) before interpreting as ATTR
Non-invasive alternative to biopsy for ATTR diagnosis
FDG-PET CT for sarcoidosis
▶
Active granulomatous inflammation detection
Sensitivity 89%, specificity 78% for cardiac sarcoidosis
Guides biopsy site and treatment response
CT chest
▶
Normal cardiac silhouette with enlarged atria
Pulmonary congestion, Kerley B lines, pleural effusions
Hilar lymphadenopathy in sarcoidosis
Ultrasound
Echocardiography (first-line imaging)
▶
Structural findings
▶
Biatrial enlargement (pathognomonic finding)
Normal or small LV cavity volume
Normal or mildly reduced LVEF (> 50% in most)
LV wall thickness variable by etiology
Granular sparkling texture in amyloidosis
Diastolic function assessment
▶
Restrictive filling pattern
E/A ratio > 2
Deceleration time < 150 ms
Elevated E/e' ratio (> 14) indicating elevated filling pressures
Tissue Doppler imaging
▶
Mitral annular e' velocity reduced (< 8 cm/s) in RCM
e' < 5 cm/s suggests severe myocardial disease
Contrast with constriction where e' often > 8 cm/s (annulus paradoxus)
Valvular assessment
▶
Mitral regurgitation grade
Tricuspid regurgitation for RVSP estimation
Exclude mitral stenosis and tricuspid stenosis
Right ventricular assessment
▶
RV diastolic dysfunction
TAPSE for RV systolic function
Biatrial enlargement pattern
Advanced echocardiographic techniques
▶
Speckle tracking strain imaging
▶
Global longitudinal strain (GLS) reduced in amyloidosis
Relative apical sparing pattern (apical GLS > basal GLS) in amyloid
Apical sparing ratio > 1 strongly suggests cardiac amyloidosis
Respirophasic septal motion
▶
Absent or minimal in RCM
Exaggerated septal bounce in constrictive pericarditis
Hemodynamic ultrasound
▶
IVC diameter and collapsibility
▶
Dilated non-collapsing IVC indicates elevated RAP
RAP estimate 15 to 20 mmHg
Pleural effusion assessment
▶
Bilateral pleural effusions common
Thoracentesis guidance if symptomatic
Cardiac catheterization
▶
Hemodynamic pattern
▶
Elevated and equalized diastolic pressures
LVEDP and RVEDP within 5 mmHg
Dip-and-plateau (square root sign) on ventricular pressure tracing
Concordant respirophasic ventricular changes
▶
Both LV and RV peak pressures rise together with inspiration
Contrasts with discordant changes in constriction
Pulmonary artery hypertension
▶
Elevated mPAP from chronic left-sided filling pressures
Severe pulmonary hypertension may preclude transplantation
Disposition
Admission criteria
Indications for hospitalization
▶
Decompensated heart failure
▶
New or worsening dyspnea at rest or minimal exertion
SpO2 < 92% on room air
Significant peripheral edema or ascites with clinical impact
Hemodynamic instability
▶
SBP < 90 mmHg
Low-output signs (cool extremities, altered mentation)
Arrhythmia
▶
New atrial fibrillation requiring rate control or cardioversion
High-degree AV block
Ventricular arrhythmia
New diagnosis requiring etiology workup
▶
Urgent echocardiogram, BNP, amyloid screening
Bone scintigraphy or CMR scheduling
Syncope
▶
Arrhythmic or low-output etiology evaluation
ICU indications
▶
Cardiogenic shock
▶
Vasopressor or inotrope requirement
Mechanical circulatory support
Respiratory failure
▶
Non-invasive ventilation or intubation
Refractory arrhythmia
▶
Hemodynamically unstable ventricular arrhythmia
Transfer criteria
Indications for transfer to advanced center
▶
Cardiac transplantation evaluation
▶
All patients with confirmed RCM and NYHA Class III-IV
Transfer to transplant-capable center
Endomyocardial biopsy requirement
▶
Inconclusive noninvasive workup
Centers with cardiomyopathy expertise
Mechanical circulatory support
▶
IABP or LVAD bridge to transplant consideration
Discharge criteria and follow-up
Copy
Outpatient criteria
▶
Hemodynamically stable
▶
SBP > 90 mmHg without symptomatic hypotension
Resting heart rate 60 to 100 bpm
Symptom improvement
▶
Dyspnea improved to near-baseline
SpO2 >= 92% on room air
Decongestion achieved
▶
Edema and ascites improved
Weight approaching dry weight target
Oral medications tolerated
Outpatient follow-up plan
▶
Cardiology within 1 to 2 weeks
Advanced heart failure clinic if available
Genetic counseling if familial RCM confirmed
Disease-specific follow-up (hematology for AL, hepatology for hemochromatosis)
Treatment
Diuretic therapy
Loop diuretics (mainstay of symptomatic treatment)
▶
Furosemide IV for acute decompensation
▶
40 to 80 mg IV initial dose
Double prior oral dose if tolerating
Continuous infusion 5 to 20 mg/hour for refractory congestion
Furosemide PO for maintenance
▶
20 to 160 mg daily or twice daily
Titrate to achieve and maintain dry weight
Torsemide PO alternative
▶
Superior oral bioavailability vs furosemide
10 to 80 mg daily
Caution with overdiuresis
▶
Noncompliant ventricle critically dependent on preload
Overdiuresis causes hypotension, prerenal azotemia, low output
Target daily weight loss 0.5 to 1 kg maximum
Thiazide or aldosterone antagonist addition
▶
Metolazone 2.5 to 5 mg PO
▶
Combination with loop diuretic for diuretic resistance
Hyperkalemia and electrolyte monitoring required
Spironolactone 25 to 50 mg daily
▶
Mild diuretic effect
Avoid if eGFR < 30 or hyperkalemia
No proven mortality benefit in RCM specifically
Rate and rhythm management
Atrial fibrillation management
▶
Rhythm control preferred over rate control
▶
Preserve atrial contractility for diastolic filling
Loss of atrial kick is particularly deleterious in RCM
Rate control when rhythm control not feasible
▶
Avoid excessive rate reduction
Heart rate dependence for cardiac output in RCM
Target heart rate 60 to 80 bpm at rest
Anticoagulation for atrial fibrillation
▶
All patients unless absolute contraindication
High thromboembolic risk in RCM with AF
Direct oral anticoagulants preferred (apixaban, rivaroxaban)
Warfarin for amyloidosis with mechanical valve or renal impairment
Conduction system disease
▶
Permanent pacemaker for high-degree AV block
▶
Sinus node dysfunction or complete heart block
Particular risk in cardiac sarcoidosis
ICD consideration
▶
Sustained ventricular arrhythmia history
Cardiac sarcoidosis with reduced LVEF or arrhythmia
Not routinely indicated for idiopathic RCM with preserved EF
Anticoagulation
Thromboembolic prophylaxis
▶
Atrial fibrillation anticoagulation
▶
Apixaban 5 mg PO twice daily (2.5 mg if >= 2 of: age >= 80, weight <= 60 kg, creatinine >= 133 micromol/L)
Rivaroxaban 20 mg PO daily with evening meal
Warfarin target INR 2 to 3
Anticoagulation for pediatric RCM
▶
Recommended at diagnosis regardless of AF status
High baseline thromboembolic incidence
Weight-based anticoagulation per pediatric hematology guidance
Disease-specific therapies
ATTR cardiac amyloidosis
▶
Tafamidis (Vyndaqel/Vyndamax)
▶
Tafamidis meglumine 80 mg PO daily
Tafamidis free acid 61 mg PO daily (Vyndamax)
ATTR-ACT trial: 30% relative risk reduction in mortality and CV hospitalization
Indicated for ATTR-CM with NYHA Class I-III
Class I recommendation in 2023 ACC/AHA guidelines
CRISPR/RNA silencing agents (for hereditary ATTR)
▶
Patisiran 0.3 mg/kg IV every 3 weeks
Vutrisiran 25 mg SC every 3 months
Primarily for hereditary ATTR with polyneuropathy
Avoid digoxin in amyloidosis
▶
Increased sensitivity to toxicity from amyloid binding
Risk of severe bradyarrhythmia
Avoid ACE inhibitors and ARBs if hypotension risk
▶
Poor tolerance due to autonomic dysfunction and low output
AL cardiac amyloidosis
▶
Hematology-directed chemotherapy
▶
Bortezomib-based regimens (VCD: bortezomib, cyclophosphamide, dexamethasone)
Daratumumab-based regimens for eligible patients
Goal: rapid suppression of clonal plasma cells
Autologous stem cell transplant
▶
Selected patients with cardiac function adequate for transplant
Cardiac transplantation alone without hematologic therapy not recommended
▶
Amyloid continues to infiltrate new heart
Hemochromatosis
▶
Therapeutic phlebotomy
▶
450 to 500 mL weekly until ferritin < 50 mcg/L
Maintenance every 2 to 4 months thereafter
Reversal of early iron cardiomyopathy possible
Iron chelation (transfusion-related overload)
▶
Deferasirox 10 to 40 mg/kg PO daily
Deferoxamine IV or SC for severe overload or intolerance
Sarcoidosis
▶
Corticosteroids
▶
Prednisone 40 to 60 mg PO daily initial dose
Taper over months guided by imaging and biomarkers
Evidence strongest for conduction disease and ventricular arrhythmia
Steroid-sparing agents for maintenance
▶
Methotrexate or azathioprine
Fabry disease
▶
Agalsidase beta enzyme replacement therapy
▶
1 mg/kg IV every 2 weeks
Slows progression when started before severe fibrosis
Migalastat for amenable GLA variants
▶
123 mg PO every other day oral chaperone therapy
Cardiac transplantation
Transplant evaluation
▶
All patients with NYHA Class III-IV despite optimal medical therapy
Contraindications
▶
Severe irreversible pulmonary hypertension (PVR > 6 Wood units fixed)
Active malignancy
Significant non-cardiac comorbidities
AL amyloidosis
▶
Sequential cardiac then autologous stem cell transplant approach in selected patients
Cardiac transplant alone without plasma cell treatment leads to amyloid recurrence
ATTR amyloidosis
▶
Combined heart and liver transplant for hereditary ATTR (liver produces TTR protein)
Heart transplant alone with tafamidis for wild-type ATTR selected cases
Bridge to transplant
▶
Mechanical circulatory support
▶
LVAD limited by RV failure risk in biventricular diastolic restriction
BIVAD or total artificial heart in selected cases
Inotrope infusion as bridge (dobutamine 2 to 10 mcg/kg/min)
Special Populations
Pregnancy
Pregnancy considerations in RCM
▶
Pregnancy generally contraindicated in advanced RCM
▶
Fixed cardiac output cannot accommodate increased circulatory demands
Maternal mortality risk is high in NYHA Class III-IV
Preconception counseling essential
Hemodynamic changes of pregnancy
▶
40 to 50% increase in blood volume
Increased heart rate and cardiac demand
Noncompliant ventricle unable to increase stroke volume
If pregnancy occurs in mild RCM
▶
High-risk obstetric and cardiology co-management
Frequent monitoring throughout gestation and postpartum
Postpartum period highest risk for decompensation
Medication safety in pregnancy
▶
Diuretics
▶
Use cautiously; avoid overdiuresis
Furosemide category C; use only if benefit outweighs risk
Anticoagulation
▶
Low molecular weight heparin preferred in first trimester and near delivery
Warfarin teratogenic especially 6 to 12 weeks gestation
Direct oral anticoagulants contraindicated in pregnancy
Tafamidis
▶
Insufficient safety data; generally avoid in pregnancy
ACE inhibitors and ARBs
▶
Absolutely contraindicated in pregnancy (fetal renal toxicity)
Beta-blockers
▶
Labetalol or metoprolol generally safer in pregnancy
Monitor for fetal bradycardia and growth restriction
Geriatric
Epidemiologic burden in older adults
▶
Wild-type (senile) ATTR amyloidosis
▶
Almost exclusively affects men > 60 to 70 years
Significant underdiagnosis historically
Prevalence rising with aging population and better diagnostics
RCM with HFpEF overlap
▶
Difficult to distinguish from hypertensive HFpEF
Bone scintigraphy clarifies ATTR contribution
Management modifications in older adults
▶
Diuresis
▶
Higher risk of orthostatic hypotension and falls
Cognitive effects from electrolyte disturbances
Slower diuresis with close renal monitoring
Anticoagulation
▶
Bleeding risk assessment (HAS-BLED score)
Renal function and drug interactions with DOACs
Apixaban has favorable bleeding profile in older adults
Tafamidis in older adults
▶
Well tolerated in ATTR-ACT trial population (mean age 74 years)
Benefit in NYHA Class I-II greater than Class III
Frailty and transplant candidacy
▶
Chronological age less important than functional and physiologic age
Transplant centers increasingly considering older recipients
Frailty indices used alongside standard criteria
Pediatrics
Epidemiology in children
▶
RCM is rare in children
▶
Less than 5% of pediatric cardiomyopathies
More common in girls
Genetic cause predominates
▶
Sarcomeric mutations (TNNI3 most common)
Comprehensive genetic testing mandatory
Prognosis is poor without transplant
▶
Two-year survival less than 50% without transplantation
Sudden cardiac death as presenting event possible
Clinical differences in children
▶
Presentation
▶
Failure to thrive
Fatigue and exercise intolerance
Syncope or sudden death as first manifestation
Pulmonary hypertension develops rapidly
▶
Severe irreversible pulmonary hypertension may preclude transplant
Close PA pressure monitoring essential
Management principles in children
▶
Diuretics
▶
Furosemide 1 to 2 mg/kg/dose IV or PO every 6 to 12 hours
Spironolactone 1 to 3 mg/kg/day PO divided once to twice daily
Careful electrolyte monitoring with weight-based dosing
Anticoagulation
▶
Recommended at diagnosis regardless of AF status
Warfarin target INR 2 to 3 in children with therapeutic monitoring
Enoxaparin 0.5 to 1 mg/kg SC twice daily alternative
Transplant listing
▶
Early listing given poor prognosis
Weight-appropriate matching
Sensitization management with IVIG if PRA elevated
Background
Epidemiology
Prevalence and incidence
▶
Least common of the three major cardiomyopathy subtypes
▶
2 to 5% of all cardiomyopathy cases
Estimated prevalence 1 to 2 per 100,000 in developed countries
Idiopathic RCM incidence
▶
Rare; true prevalence difficult to estimate
Likely underdiagnosed due to overlap with HFpEF
ATTR amyloidosis incidence increasing
▶
Rising detection due to bone scintigraphy and improved awareness
Wild-type ATTR affects up to 25% of men > 80 years at autopsy
Demographics
▶
Age distribution
▶
Idiopathic RCM: any age including children
ATTR wild-type: predominantly men > 60 to 70 years
AL amyloidosis: median age 65 years at diagnosis
Sex distribution
▶
Idiopathic RCM: female predominance in children
ATTR wild-type: male predominance (> 90%)
Fabry disease: predominantly males (X-linked) though females can be affected
Racial distribution
▶
Val122Ile TTR variant: carrier frequency 3 to 4% in African Americans
Cardiac sarcoidosis higher incidence in African Americans
Mortality and prognosis
▶
5-year survival approximately 30 to 50% for idiopathic RCM
Children with RCM 2-year survival < 50% without transplantation
AL amyloidosis median survival < 6 months untreated, improving with modern chemotherapy
ATTR amyloidosis median survival 3 to 4 years without tafamidis
Pathophysiology
Core hemodynamic abnormality
▶
Impaired ventricular filling
▶
Myocardial stiffness with noncompliant ventricular walls
Rapid rise in ventricular pressure with minimal increase in filling volume
Diastolic heart failure (HFpEF physiology at extreme)
Preserved systolic function (initially)
▶
LVEF normal or near normal
Stroke volume reduced due to underfilling
Markedly elevated filling pressures
▶
Elevated LVEDP and RVEDP
Equalized diastolic pressures (LVEDP = RVEDP within 5 mmHg)
Backward failure causing pulmonary and systemic venous congestion
Non-dilated ventricles
▶
Distinguishes RCM from dilated cardiomyopathy
Biatrial enlargement from chronic pressure load
Rate dependence and fixed stroke volume
▶
Cannot increase stroke volume with exercise
Cardiac output increase dependent on heart rate
Tachycardia reduces diastolic filling time paradoxically
Underlying disease mechanisms by etiology
▶
Amyloid infiltration
▶
Amyloid fibrils deposited in myocardial interstitium
Extracellular volume expansion and myocyte compression
TTR or AL light chain protein misfolding and aggregation
Sarcoid granulomas
▶
Non-caseating granulomas replace functional myocardium
Conduction system involvement causing AV block
Fibrosis and scar replacing granulomas in healing phase
Iron overload
▶
Iron deposition in cardiomyocytes
Oxidative stress and cellular injury
Fibrosis from iron-mediated damage
Sarcomeric mutations
▶
Altered force generation and relaxation
Myofibrillar disarray and interstitial fibrosis
Phenotypic overlap with HCM
Pulmonary hypertension development
▶
Chronically elevated pulmonary venous pressures
▶
Passive reactive pulmonary hypertension initially
Progressive pulmonary vascular remodeling
Fixed pre-capillary component may develop
Severe fixed pulmonary hypertension precludes transplantation
Therapeutic Considerations
Diuretic philosophy in RCM
▶
Congestion relief vs preload preservation tension
▶
Ventricular filling requires adequate preload
Aggressive diuresis causes hypotension and low output
Targeted toward symptom relief at minimum effective dose
Diuretic resistance mechanisms
▶
Reduced GFR from low cardiac output
Increased sodium reabsorption from RAAS activation
Combination diuretic strategy addresses different nephron segments
RAAS blockade limitations
▶
ACE inhibitors and ARBs
▶
Vasodilation causes hypotension in underfilled, fixed-output state
No proven mortality benefit in RCM
Use only if hypertension is present and tolerated
ARNI (sacubitril/valsartan)
▶
Data limited in RCM specifically
Hypotension risk
Beta-blockade caution
▶
Rate dependence for cardiac output
▶
Heart rate reduction decreases cardiac output in RCM
Avoid negative chronotropy unless clear arrhythmia indication
Calcium channel blockers
▶
Verapamil and diltiazem similarly reduce heart rate and contractility
Negative inotropic effect harmful in borderline EF
Transplant as definitive therapy
▶
Only proven survival benefit for idiopathic and sarcomeric RCM
Disease recurrence risk
▶
Amyloidosis recurs without treating underlying clonal disease (AL) or TTR source (hereditary ATTR)
Sarcoidosis can recur in transplanted heart
Waitlist mortality high; early referral critical
Disease-modifying treatment evidence
▶
Tafamidis (ATTR-CM)
▶
Stabilizes TTR tetramer preventing amyloidogenesis
Class I recommendation in 2023 ACC/AHA HF guidelines
Iron reduction (hemochromatosis)
▶
Early intervention reverses cardiomyopathy
Genetic family screening essential
Sarcoid immunosuppression
▶
Corticosteroids reverse active inflammatory phase
Fibrotic stage less responsive
Patient Discharge Instructions
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Restrictive cardiomyopathy home care
▶
Take all heart medications exactly as prescribed
Low sodium diet, 2 to 4 grams per day
Fluid restriction, approximately 1.5 to 2 litres per day
Weigh yourself every morning after using the bathroom and before eating
Keep a daily weight log
Elevate legs when sitting to reduce swelling
Warning signs to return to Emergency Department immediately
▶
Sudden or rapidly worsening shortness of breath
Swelling that gets rapidly worse (legs, abdomen)
Weight gain of more than 2 kg over 2 days
Fainting, passing out, or near-fainting
Rapid or irregular heartbeat with dizziness or chest discomfort
Chest pain or pressure
Confusion or unusual drowsiness
Very low urine output despite drinking enough fluids
Activity and lifestyle instructions
▶
Avoid strenuous exercise unless specifically approved by your cardiologist
Light daily activity such as gentle walking as tolerated
Avoid alcohol
No smoking
Avoid excessive heat (hot tubs, saunas) which can cause blood vessel dilation and low blood pressure
Medication notes
▶
Do not stop water pills (diuretics) without calling your doctor
If you miss a dose of diuretic, do not double the next dose
Blood thinners (anticoagulants) require regular blood tests or monitoring
If on tafamidis, take daily without interruption
Follow-up
▶
Cardiology appointment within 1 to 2 weeks
Bring all medications to each visit
Genetic counseling referral if hereditary cardiomyopathy suspected in your family
If you have amyloidosis or sarcoidosis, keep all specialist appointments
References
Guidelines and key sources
Society guidelines
▶
2023 ACC/AHA Heart Failure Guideline (Heidenreich et al., JACC 2022)
▶
Class I recommendation for tafamidis in ATTR-CM NYHA I-III
Heart failure staging, management, and transplant criteria
2020 ESC Guidelines on Heart Failure
▶
Diagnosis and management of RCM
Diuretic and anticoagulation recommendations
HRS Expert Consensus Statement on Evaluation and Management of Arrhythmias in Cardiac Sarcoidosis (2014)
Key clinical trials
▶
ATTR-ACT trial (Maurer et al., NEJM 2018)
▶
Tafamidis reduced all-cause mortality and cardiovascular hospitalization
30% relative risk reduction vs placebo in ATTR-CM
APOLLO-B trial (Adams et al., NEJM 2023)
▶
Patisiran reduced CV events in hereditary ATTR with polyneuropathy
HELIOS-B trial (Solomon et al., NEJM 2024)
▶
Vutrisiran reduced mortality and CV events in ATTR-CM
Diagnostic references
▶
Expert consensus on cardiac amyloidosis diagnosis (Dorbala et al., JACC 2019)
▶
Bone scintigraphy algorithm for ATTR diagnosis
Multimodality imaging approach
AHA Scientific Statement on RCM (Muchtar et al., Circulation 2021)
▶
Epidemiology, etiology, diagnosis, and management
Coding references
▶
ICD-10 I42.5 Other restrictive cardiomyopathy
ICD-10 E85.4 Organ-limited amyloidosis (cardiac amyloidosis)
ICD-10 D86.85 Sarcoid myocarditis
SNOMED CT 415068001 Restrictive cardiomyopathy
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.
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Restrictive Cardiomyopathy