Table of contents
- 1. Cardiomyopathies
- 2. Notes on Specific Types
- 2.1. Amyoidosis
- 2.2. Sarcoidosis
- 3. Myocarditis
- 4. Constrictive vs. Restrictive vs. Tamponade
- 4.1. Hemodynamics
- 5. Takotsubo Cardiomyopathy
- 6. Tachycardia-Induced Cardiomyopathy
- 7. Acute Myocarditis
- 8. Hypertrophic Cardiomyopathy
- 8.1. HCM Mimics
- 8.2. Complications
- 8.3. Management
- 9. Cardiac Tumors
.
Cardiomyopathies
- Restrictive Cardiomyopathy (RCM)
- Hypertrophic Cardiomyopathy (HCM)
- Dilated Cardiomyopathy (DCM)
- ArrythmogenicRight Ventricular Cardiomyopathy (ARVC)
Restrictive Cardiomyopathy (RCM)
- Infiltration or fibrosis of the myocardium causing impaired ventricular filling with preserved systolic function.
- Reduced or normal diastolic ventricular cavity volume + stiff ventricular myocardium.
- Causing high filling pressures with small amounts of volume.
- Early in course biventricular systolic function is normal, but can deteriorate later in disease.
- Systolic function may diminish in end-stage disease
- Typical have RAPID early diastolic filling on echo (and JVP - Prominent x/y descents)
- NOTE: Constrictive pericarditis vs. restrictive cardiomyopathy --> RV and LV share same space in constrictive pericarditis. Relative increase in filling of RV, which restricts LV filling and vice versa. Look for this ventricular interaction on echo.
- Also restrictive cardiomyopathy have higher BNP levels than constrictive pericarditis. (>800)
- Causes:
- Infiltrative (rule these out!)
- Amyoidosis
- Sarcoidosis
- Hemochromatosis
- Non-Infiltrative
- Scleroderma
- Radiation
- Fibrosis following cardiac surgery
- Myocardial Storage Conditions
- anthracyclines (doxorubicin, donorubicin)
- Infiltrative (rule these out!)
- Symptoms:
- Dyspnea, fatigue, peripheral edema
- Exam:
- Elevated JVP (increases with inspiration - Kussmaul's Sign)
- Normal LV impulse
- If advanced: Heptosplenomegaly + Ascites
- DDx:
- Hypertrophic cardiomyopathy, Dilated cardiomyopathy
- Constrictive pericarditis: Clinical presentation and physical exam may yield findings identical to RCM.
- MRI shows pericardial thickening(>5mm), and right heart catheterization demonstrates equalization of diastolic pressures in contrictive pericarditis.
- Diagnosis:
-
- ECG
- Conduction System Disease
- Low QRS voltage
- Nonspecific ST-T wave changes
- Echocardiography
- Restrictive filling pattern (preserved systolic function)
- (If infiltrative, myocadium can look granular)
- Biatrial enlargement
- R-Heart Catheterization
- Dip & plateau vetnricular filling ("Square root sign")
- Pulmonary hypertension
- Respiratory concordance of ventricles
- Myocardial Biopsy
- Detects infiltrative disease (amyoidosis & sarcoidosis)
- ECG
- Treatment
- Treat underlying disease
- Diuretics
- Can improve symptoms, but hard b/c overdiuresis causes hypotension (preload dependence, no cardiac index)
- B-Blockers & CCB
- Can improve diastolic function early in disease. (slow heart rate & increase filling time)
- Caution: can drop cardiac output
- CCB: careful in amyloid (causes negative inotropy & conduction problems)
- Cardiac transplant
- If no systemic disease
Hypertrophic Cardiomyopathy (HCM)
- Autosomal-dominant disorder of myocardial structural proteins that causes premature, severe LVH
- A subset of HCM can cause asymmetrical septal hypertrophy causing dynamic outflow tract obstruction (HOCM!)
- Symptoms:
- Syncope, chest pain, dyspnea
- Exam:
- If LVOT Obstruction:
- Systolic crescendo-decrescendo murmur that
- intensivies with reduction of LV volume (Standing, valsalva)
- Decreases with increase LV volume (handgrip, raising legs when supine, stand to sit)
- Systolic crescendo-decrescendo murmur that
- S4 and sustained apical impulse are characteristic
- Carotid upstrokes bifid (mid-systolic obstruction)
- If LVOT Obstruction:
- Treatment:
- Agents that DECREASE LV VOLUME (preload) such as nitrates & diuretics increase LVOT obstruction --> contraindicated in HCM!
Notes on Specific Types
Amyoidosis
- Heart failure, hepatomegaly, proteinuria, bruising
- Low voltage ECG (despite increased wall thickness on echo)
- Diagnose with: sPEP, uPEP, abdominal fat pad or gingival biopsy
- Cardiac involvement = BAD prognosis
Sarcoidosis
- Patchy involvement of the myocardium (inflammation & fibrosis due to granuloma formation)
- Myocardium is not replaced or displaced hence ECG = normal! (not low voltages like Amyoid)
- Systemic Symptoms:
- Pulmonary Involvement
- Skin involvement
Myocarditis
Giant Cell Myocarditis
- Presents with heart failure & cardiogenic shock within several days (can be up to months) of onset.
- Often refractory ventricular arrhythmias
- High mortality rate
- Does not have systemic symptoms (unlike amyloid)
Constrictive vs. Restrictive vs. Tamponade
Condition | History | ECG | Physical Exam | CXR | ECHO |
---|---|---|---|---|---|
Constrictive Pericarditis | TB, Cardiac Surgery, Radiation, CTD, Trauma, Prior Pericarditis | Nonspecific | Pulsus Par. - may have JVP (prominent x/y descents, Kussmauls) Heart Sounds (pericardial Knock) | Pericardial Calcification | Pericardial Thickening Pericardial Effusion (Sometimes) Ventricular septal flattening with inspiration |
Restrictive CM | Amyoid, Sarcoid, Hemochromatosis, etc.. | - R or L Atrial Enlargement - AV Delay, BBB | Pulsus Par. - RARE JVP - Prominent x/y descents - Kussmaul's Heart Sounds - S4 Murmurs - MR, TR | ---- | - Atrial Enlargement - Mod/Severe Diastolic Dysfunction |
Cardiac Tamponade | Prior effusion, cardiac surgery, malignancy (i.e. breast Ca), recent MI | Low Voltage, Electrical Alternans | Pulsus Par. - Frequent JVP - Abscent/diminished y-descent Heart Sounds - muffled Murmurs - NONE | Cardiomegaly Globular Heart | - Pericardial Effusion - RV collapse during systole |
Hemodynamics
Constrictive Pericarditis | Restrictive CM | Cardiac Tamponade | |
---|---|---|---|
Equalization of diastolic pressures | YES | L-side is higher (LV more restricted) | YES |
Dip & Plateau (Square Root Sign) | YES (restricts at end) | YES (Restricts at end) | NO (restricts entire cycle) |
Respiratory Variation in LV/RV Pressures | Discordant peak RV and LV pressures (outline restricts/pulsus) | Concordant peak RV and LV pressures (septum restricts too!) | Variable, likely discordant (Outline restricts/pulsus) |
Takotsubo Cardiomyopathy
- Aka stress-induced cardiomyopathy
- Transient cardiac dysfunction... apical ballooning triggered by emotional stress. (in some cases no trigger identifiable).
- Presenting picture looks like ACS:
- Chest pain, troponin, ischemic ECG
- Echo or ventriculogram make diagnosis. (absence of CAD).
- Treatment:
- B-blocker therapy + supportive, but does not protect against recurrence.
- Ejection fraction quickly normalizes, but small percentage take months to recover.
Tachycardia-Induced Cardiomyopathy
- Months to years of tachycardia.
- Atrial or ventricular tachycardia.
- Frequent PVCs can cause this (>1000 per day).
- Rate control improves or resolves cardiomyopathy.
- Recurrence occurs fast if tachycardia recurs.
Acute Myocarditis
- Inflammation of myocardium
- Many causes: toxins, infections (most common: viral infections).
- Pathophysiology is unkown.
- Symptoms (range):
- From minor symptoms to cardiogenic shock.
- Treatment:
- Immunosuppressives do not benefit.
- Supportive care, and therapy for systolic HF for any cause.
- Fulminant presentations (acute, cardiogenic shock), have higher recovery rates.
Giant-Cell Myocarditis
- Form or acute myocarditis (often fatal), affecting those in 40's.
- Characterized by: rapid onset of fulminant heart failure (days-months).
- Refractory ventricular arrhythmias are common.
- Mechanism unknown, thought to be autoimmune.
- Treatment:
- Immunosuppressives (steroids etc..) do not change outcomes.
- Often need mechanical support or transplant.
Hypertrophic Cardiomyopathy
- Primary myocardial diesease: Diffuse or focal LV hypertrophy in the absence of afterload-increasing conditions (AS, HTN, etc.)
- Prevalence: 0.02%. 50% have familial origin.
- Most common patern: ASH (Asymmetric Septal Hypertrophy)
- Often benign
- Complications:
- Syncope
- Arrhythmia
- Ischemia
- HF
- Stroke.
- Annual mortality: 3-6%.
- Suspicions:
- Often sent for screening when family members found this.
- Often have angina, dyspnea, palpitations, fatigue, dizziness, true syncope.
- Diastolic dysfunction.
- Myocardial ischemia
- LV outflow tract obstruction
- AFib
- On Exam:
-
- Mid-systolic murmur caused by LVOT obstruction.
- Valsalva or Squat-to-Standmanouvres, decrease preload, shrinks chamber, more opposition of hypertrophic muscles, murmur becomes louder (40% sensitivity, quite poor)
- If lift legs, increasepreload, murmur gets quieter.
- NOTE: Other causes LVOT obstruction (HOCM is a dynamic obstruction).
- EKG:
- Increased QRS voltage, ST abnormalities (repolarization abnormalities). (many have normal EKG).
- Prominent Q-waves (i.e. infero-lateral) are not due to infarcts, due to septal hypertrophy (T-waves upright in leads with Q-waves).
- Diagnosis:
- On Echocardiography (≥15mm septum).
- Often LVEF ok, but diastolic dysfunction and L-atrial enlargement.
- Often hyperdynamic LV with small cavity.
- Often need Stress Echocardiogram!!!
- 40-50% of patients have provokable obstruction on exercise
- Or any other afterload reduction agent (like amyl nitrite, dobutamine).
-
Diagnosis of HCM on Echo:
- Resting gradient >30mmHg or provokable gradient of >50mmHg is diagnostic.
- On Echocardiography (≥15mm septum).
- SAM (Systolic anterior motion of the mitral valves)
- Most common mechanism of dynamic outflow tract obstruction.
- Anterior leaflet of the mitral valve is pushed into the hypertrophied basal septum causing obstruction.
- The anterior leaflet is then separated from posterior leaflet during systole (should be coapting) --> causing MR that is often directed posterior into the atrium.
- In HCM, SAM is prolonged
Continuous-wave Doppler after exercise stress testing in a pt with hypertrophic cardiomyopathy (left panel) demonstrates a high-velocity late-peaking systolic waveform (arrow) across the LVOT from an exercise-provoked dynamic obstruction. Peak velocity is 4.48 M/sec, indicative of a peak gradient of 80 mm Hg. For comparison, the right panel shows pulsed Doppler echocardiography across the left ventricular outflow tract in a patient without hypertrophic cardiomyopathy. There is an earlier-peaking systolic waveform (arrow) with a normal velocity of 0.9 M/sec, indicative of no outflow gradient. Note the difference in velocity scales.
HCM Mimics
- Athlete's Heart
- Athlete is elitely trained in exercise with aerobic and anaerobic demands develops LVH.
- Lesser degree of hypertrophy (<15mm of any wall thickness), cavity volume enlarged due to high volume state (rather than reduced in HCM)... Also no LA enlargement.
- Infiltrative causes (Sarcoid, Amyloid) --> often symmetric and concentric wall thickening (HCM is asymmetric)
- Cardiac MRI or PET helps separate them from HCM (delayed hyper-enhancement).
- Fabrey's Disease (alpha-galactosidase enzyme deficiency)
Complications
- High risk of atrial fibrillation (need atrial kick), may precipirate heart failure and stroke.
- Some patients can progress to dilated CMTHY with impaired systolic function.
- Sudden death, heart failure, stroke.
- Sudden death is infrequent --> more common in young (15-35yo).
- High risk if :
- Prev cardiac arrest
- VTach
- 1st deg family member with sudden cardiac death with known HCM
- Recurrent unexplained loss of consciousness (hard to separate from obstructive)
- Extreme increased wall thickness (>30mm [normal <10mm])
- Abnormal blunted BP response during exercise, if BP fails to rise during exercise.
- NSVT (even if asymptomatic on ambulatory ECG).
- High risk if :
Management
- Lifestyle changes
- Level of exercise (Moderate level of exercise - not competitive or strenuous. Avoid activities that require sudden intense bursts of energy such as full court basketball, soccer, football). These are considered high risk for provoking sudden death.
- Medical therapy warranted if symptomatic.
- Beta-Blockers - reduce HR, diastolic filling, LV contarctility, dynamic LVOT obstruction.
- CCB (verapamil) - can use if don't tolerate BB
- Do not combine with BB due to negative inotropy (severe bradycardia).
- Vasodilatory effect can cause worse LVOT obstruction, severe symptoms.
- Disopyramide
- Very old antiarrhythmic.
- Very negative inotropic agent, used in addition to BB therapy.
- Can prolong QT interval / QRS duration.
- Avoid worsening outflow gradient
- Exercissive diuresis, vasodilators, digoxin.
- Device therapy
- Pacemaker
- For those with bradycardia during medical titration
- Not used to reduce LVOT obstruction.
- ICD
- All HCM patients should receive ICD regardless of presence of symptoms.
- Primary prevention of sudden cardiac death for HCM and multiple RFs for sudden death.
- Indicated for LV systolic dysfunction with LVEF <35%.
- Pacemaker
- Heart transplant
- For refractory symptoms that cannot be managed medically
OR - Progressive systolic dysfunction
OR - Refractory ventricular arrhythmias
- For refractory symptoms that cannot be managed medically
- Atrial Fibrillation
- Same rules for anticoagulation, but rhythm control may be preferred to maintain ventricular filling.
- AFib ablation, amiodarone are options.
- Septal Reduction therapy
- Reduce thickness of basal septum to reduce systolic anterior motion of mitral valves => greater forward flow / (stroke volume). Very significant surgery!
- Only for medically-refractory cases, and severe cases.
- However, operativive mortality is quite low (<1%), improves symptoms, quite effective for LVOT.
- NEW: Alcohol Septal Ablation
- Catheter passed into septal perforator artery that supplies the hypertrophied part of ventricle with blood.
- Alcohol injected into that area, causing therapeutic infarction.
- Initially area remains thick, but over time will thin, reducing LVOT.
- No trials comparing these two therapies.
- Concern about scar causing future arrhythmias.
- Genetic counselling. (autosomal dominant) --> screen family members.
- Many genes in effect. (Sarcomeric proteins).
- Negative echo in family member does not rule out HCM...
- 1st degree relatives should undergy q5y echo screening in adulthood to ensure no late-onset HCM.
- In adolescence echo q1year.
Cardiac Tumors
- Atrial Myxomas (L-atrial 80% of the time).
- Atrial myxomas must be surgically removed (especially if L-sided) to avoid embolic phenomena even in asymptomatic patients.
- Rhabdomyosarcomas (show up bright on echo)
- Fibroelastoma (attached to heart valves or mitral cordal aparatus)
- Can also present with stroke or another embolization phenomena.
- Secondary tumors 20 times more common than primary. Originate from lung or breast carcinomas + renal, hepatocellular etc.
- Cardiac tumors often cause non-specific symptoms... often heart failure and pericardial constriction.
- Occasionally syncope, stroke (embolization), heart block (invasion), Ventricular arrhythmias.
- Echo is gold standard in identifying tumors. TEE specifically is more effective.
- Generally requires surgical removal, and sent for biopsy.
- (can't biopsy in cath lab, high risk of embolization).
- If not removed, very high risk of embolization despite anticoagulation.
- Malignant tumors are not amenable to curative surgery.
Comments