Cardiomyopathies Flashcards
Cardiomyopathy definitions
A heterogenous group of diseases of the myocardium, charactersied by mechanical and.or electrical dysfunction that typically (though no invariably) exhibit inapproriate ventricular hypertrophy or dilation and are due to a variety of causes that are frequently genetic.
Classifications
Classified according to predominant organ involvement:
- Primary (confined to the heart) (subdivided into genetic and aqcuired forms)
- Seondary (occur as part of a variety of generalised systemic diseases)
Dilated cardiomyopathy definition
Characterised by cardiac chamber enlargement and weakned with mpaired systolic dysfunction, although diastolic dysfunction is almost always also present
Symptoms of dilated cardiomyopathy
- abrupt presentation
- acute pulmonary oedema, systemic or pulmonary emboli
- more often patients present with progressive symptoms of congestive heart failure (exertional dyspnoea, orthopnoe, paroxysmal nocturnal dyspnoea and fatigue)
- RUQ discomfort
- nausea
- Anorexia due to hepatic ongestion
Diagnosis of dilated cardiomyopathy
Diagnosis is established by PE, electrocardiography, chest x ray and echo
- Raised JVP, disaplaced cardiac apex, and added heart sounds- sensitive clinical markers of heart failure
- ECG - evidence of sinus tachy, or AF
- CXR - cardiomegaly, pulmonary oedema and (kerley B lines, and plerual effusions)
- ECHO- Gold standard
- indices of systolic function are impaired
- complications of cardiac muopathy (intramural thrombus and alternative causes of heart failure )
- Exercise testing - functional capcity and prognosis
- Ambulatory ECG - identifies the presence of paroxysmal AF and VT
Treatment of Dilated Cardiomyopathy
Management focuses on reliving symptoms and improving prognosis and quality of life:
- Loop diuretics - For peripheral and pulmonary congestion (monitor electrolytes, or give spironolactone alongside)
- ACE-I - heart failure (dry cough common, angiooedema life threatening)
- Beta blockers - reduction of myocardial oxygen consumtion
- Aldosterone antagonists - Improve symtpms and prognosis
- Anti-arrhythmic agents - Most patients are given beta blockers as rate control for AF however, may be given digoxin who have rapid heart rates despite B blockers
- Anti-coagulation - patients are prone to thromboembolic events and should be given warfarin
- Device therapy - CRT (ventricular pacer) or ICDS (implantable cardioverter defibs)
- Cardiac transplant - considered in severely symptomatic and despite max medical therapy
Hypertrophic cardiomyopathy definition
Unexplained Left ventricular hypertrophy associated with non-dilated ventricular chambers in the absence of another cardiac or systemic disease capable of producing the magnitude of hypertrophy evident.
Symptoms of HCM
- usually aysymptomatic
- fatigue and breathlessness due to impaired diastolic filling and decreased cardiac output
- chest pain (angina)
- palpitations and syncope
- sudden death
Signs of HCM on examination
- LVH - forceful apical impulse)
- outflow tract obstruction - double apical impulse and ejection systolic murmur beginning in mid-systole (valsalva or squatting)
Investigations for HCM
- ECG - ST and T wave inversions, LVH with Romhilt-Estes points score >5, pathological Q waves in inferior and lateral leads , WPW syndrome ,AF
- Echo - gold standard
- asymmetrical septal hypertrophy
- small LV cavity
- mid-systolic aortic valve closure
- CMR - apical HCM
Treatment of HCM
Half sudden deaths occur during or short after strenous exercise
1) ameliorating symptoms including abolition of LVOT obstruction
2) treatment of arrhythmias
3) identification of individuals at risk of SCD with a view to implantation of ICD
4) screening first degree relatives
- Symptoms - Beta blockers, or CCB if not tolerated
- Arrhythmias - BB and amiodarone
- Abolition of LVOT obstruction - Drugs (BB or verapamils), surgical myomectomy (debulks proximal septum)
