Cardiomyopathy Flashcards
(27 cards)
What are the major risk factors for sudden cardiac death in HOCM?
Major risk factors for SCD in HCM are
- severe LVH (>30mm)
- unexplained syncope
- personal/family history of sudden cardiac arrest
- documented NSVT.
Abnormalities seen in postural orthostatic tachycardia
- The key abnormality in postural orthostatic tachycardia syndrome is that the HR should markedly and
exaggeratedly increase on standing. - The typical cut-off criteria are that HR should increase >30 beats/min or to >120bpm on standing, without any significant postural hypotension.
What should you be concerned about if a patient has ongoing symptoms despite treated pericarditis
- Constrictive pericarditis is a really important diagnosis to consider in the patient whose symptoms
don’t settle post resolution of pericarditis. - Suggestive clinical features are recurrent presentations with right heart failure (development of constrictive physiology increasing back-pressure) and development
of pericardial calcification. - Specific diagnosis is made on echocardiography which will show haemodynamic features of constriction (ventricular interdependence, annulus reversus, hepatic vein reversal during diastole in expiration etc). Treatment is initially medical (steroids, re-challenge with
anti-inflammatories), but patients may ultimately require pericardiectomy
What infections cause myocarditis?
The most common causes are adenovirus, coxsackievirus, and enterovirus (ACE)
HOCM
- Mode of inheritance
- Pathophysiology
Autosomal dominant with high disease penetrance
- Diastolic dysfunction and dynamic left ventricular outflow tract obstruction
- Dynamic LVOT obstruction is exacerbated by any therapy that increases contractility, eg: digoxin or other inotropic agents
- Worsened by reduced ventricular preload, eg: dehydration
HOCM symptoms
- Most patients with HCM have minimal or no symptoms.
However, a subset develop
- exertional dyspnea
- angina
- presyncope, or syncope.
- Sudden cardiac arrest may be the initial manifestation of the disorder.
HCM accounts for approximately 35% of sudden deaths among all persons younger than 35 years and is the leading cause of sudden death in this
age group.
Examination findings of HOCM
- Ejection systolic murmur over left lower sternal murmur
- Augmentation of the murmur occurs during maneuvers that decrease preload (swuat to stand, valsalva)
Note: AS and MR decrease with maneuvers that reduce preload
Ix for HOCM
ECG: left ventricular hypertrophy
TTE: LVOT obstruction gradient >30 at rest or >50 with provocation
Diastolic dysfunction but normal systolic function
asymmetric hypertrophy of the interventricular septum
Indications for ICD in HOCM
Placement of an implantable cardioverter defibrillator should be considered in patients with hypertrophic cardiomyopathy with one or more major risk factors for sudden cardiac death:
- prior cardiac arrest
- massive myocardial hypertrophy
- family history of sudden cardiac death
- ventricular tachycardia
- blunted blood pressure response to exercise
- unexplained syncope
Management of HOCM
- The major management goals for patients with HCM are alleviation of symptoms, risk stratification for sudden cardiac death,
ICD implantation for those at high risk, and family counseling. - Abstain from competitive sports or strenuous
aerobic activities is advised for all patients. - Avoid dehydration and states of severe peripheral vasodilatation, such as from hot baths or saunas.
- Pregnancy generally is well tolerated, although
precautions should be taken to minimize peripheral vasodilatation as for all patients with HCM.
Pharmacological agents for HOCM
Negative inotropic agents are the cornerstone of medical therapy for patients with symptomatic obstructive HCM
- B blockers
- Nondihydropyridine calcium channel blockers
- verapamil
- Disopyramide
They all depress contractility, thereby reducing the intraventricular flow velocities that predispose
to LVOT obstruction. These agents also lengthen diastole, facilitating more time for ventricular filling.
What medications should be avoided in HOCM
Positive inotropes (such as digoxin), vasodilators, and high dose diuretics should be avoided, as these drugs exacerbate LVOT obstruction
Nitrates
ACEi
Surgery for HOCM
- For patients with persistent, severe, drug-refractory symptoms caused by obstructive HCM, septal reduction therapy with surgical septa! myectomy or percutaneous alcohol septal ablation
should be considered.
Surgical myectomy is the gold standard therapy for relief of LVOT obstruction.
Need to screen first degree relatives
Difference between dilated, hypertrophic and restrictive cardiomyopathy
DILATED
- Major Abnormality: impaired contractility
- Wall thickness: usually low, normal
- Dimensions: left ventricle dilation
- EF: reduced - systolic dysfunction with normal diastole
HYPERTROPHIC
- Major Abnormality: impaired relaxation
- Wall thickness: increased ++
- EF: normal in early stages
RESTRICTIVE
- Major Abnormality: impaired elasticity
- Wall thickness: usually usually increased +
- Dimensions: normal
- EF: Normal
Features of dilated cardiomyopathy
- Thin ventricular walls, left ventricle dilation, decreased EF (systolic dysfunction with normal diastole)
- Most common subtype - 90%
Mainly are idiopathic Secondary Causes - Ischaemic cardiomyopathy - Toxins/cocaine abuse - Nutritional deficiencies, eg: thiamine deficiency (beri-beri) or selenium deficiency - Myocarditis: inflammation of the heart muscle Viruses (eg: Coxsackie B) Autoimmune Disease (eg: Lupus)
systolic murmur: stretching of the valves may result in mitral and tricuspid regurgitation
What medications cause cardiomyopathy?
Doxorubicin
Trastuzumab
Paclitaxel
Cyclophosphamide
Poor prognostic factors for HOCM
RF for sudden cardiac death in HOCM
• Recurrent syncope
• family history of sudden death
• young age at presentation
• non-sustained ventricular tachycardia on 24 or 48-hour Holter monitoring
• abnormal blood pressure changes on exercise (decrease with exercise)
- Severe LVH
- Severe obstruction
- Specific genotypes - Arg718Trp mutation
Features of restrictive cardiomyopathy
LEAST COMMON AND RARE
- The heart muscle is stiff preventing it from relaxing during diastole - diastolic dysfunction, normal systole (heart muscle is stiff which restricts diastole)
Causes:
- Primary Diseases (Idiopathic)
Endomyocardial fibrosis where excessive collagen tissue is deposited in the heart muscle
Elevated eosinophil count and deposition of eosinophils in the endocardium and myocardium –> Loeffler’s eosinophilic endocarditis
Secondary Systemic Diseases - they all cause fibrosis of the myocardium
- Amyloidosis
- Sarcoidosis
- Haemochromatosis
- Radiation Therapy
ECG: when due to amyloidosis leads to low voltage QRS complexes, due to diffuse infiltration of the heart muscle (low voltage also seen in pericardial effusion)
- Restrictive cardiomyopathy is characterized by severe diastolic dysfunction and, frequently, pulmonary hypertension –> predominantly RIGHT heart failure
- Restrictive cardiomyopathy is a diagnosis of exclusion and must be distinguished from constrictive pericarditis, eosinophilic syndromes, and infiltrative diseases
- Atria dilated - A fib common
- AV regurg common
Tx: response poor
Heart sounds in cardiomyopathy
- Dilated and Restrictive Cardiomyopathy: S3 Heart Sound as a result of blood rushing and slamming into the dilated ventricular wall during diastole
- Hypertrophic Cardiomyopathy: S4 Heart Sound in Apex of Heart which indicates that the atrium is contracting against a thickened left ventricle
Difference between restrictive pericarditis and constrictive pericarditis
- Both restrictive cardiomyopathy and constrictive pericarditis present with elevation of diastolic pressures and heart failure that is disproportionate to the degree of systolic dysfunction.
- Pericardiectomy will result in symptom relief and improvement in longevity in patients with constriction.
BNP
- Elevated in restrictive cardiomyopathy
- Normal or mildly elevated in constrictive pericarditis
Apical HOCM
- Anterior TWI in asian patient
- Left ventricular hypertrophy with increased precordial voltages and non-specific ST segment and T-wave abnormalities
- Deep, narrow (“dagger-like”) Q waves in lateral (I, aVL, V5-6) +/- inferior (II, III, aVF) leads
- Giant T waves in precordial leads
- Apical hypertrophic cardiomyopathy (AHCM) is a rare form of hypertrophic cardiomyopathy (HCM) which usually involves the apex of the left ventricle and rarely involves the right ventricular apex or bot
Amyloidosis
- Extracellular deposits of fibrils of low molecular weight protein subunits
- Usually deposit as antiparallel beta pleated sheets
- Congo Red stain: apple-green biorefringence
- AL amyloid (primary) – plasma cell dyscrasia (?multiple myeloma)
- AA amyloid (secondary) – eg RhA, IBD, chronic infection
- Other: dialysis related, heritable, age related, organ specific
- ATTR amyloid – wild type or inherited, infiltrative cardiomyopathy
Cardiac involvement of amyloidosis
- Likelihood/extent of cardiac disease varies w/ amyloid type
- Most commonly seen in AL amyloid and ATTR amyloid
- AL – cardiac involvement present in ~50%, predominant manifestation in 20-30%
- ATTR amyloid – TTR mutation or “wild-type” TTR
TTR mutation: cardiomyopathy, neuropathy or both depending on mutation type
Wild-type TTR=senile systemic amyloid. Cardiac deposits common, variable clinically importance. Atrial deposits correlate with AF
Rarely wild-type TTR - massive ventricular deposition & HF (senile cardiac amyloid)
Presentation of amyloidosis
Clinical features
- HFpEF, low voltage ECG, AF
- Heart failure - esp raised JVP and peripheral oedema/ascites
- Hypertension very rare (low output state)
- AF common
- Hepatomeagly
- Periorbital purpura – if present with HF usually AL amyloidosis
- ECG – low voltage, AF (sometimes 1st degree AV block or other conduction disease)
- High NT pro-BNP in almost all cases (>3000ng/L poor prognosis)
- Ventricular hypertrophy on echo
