Lesson topic №28. Болезни миокарда (Myocarditis and Cardiomyopathy)
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Hypertrophic cardiomyopathy: evaluation
Echocardiography is central to the diagnosis and monitoring of HCM.
In most patients, hypertrophy preferentially involves the interventricular septum in the basal LV segments but often extends into the lateral wall, the posterior septum and LV apex.
Hypertrophic cardiomyopathy: evaluation
Various patterns of left ventricular hypertrophy that can be found in HCM patients.
A Predominant asymmetric septal hypertrophy.
B Concentric, symmetric hypertrophy.
C Apical hypertrophy.
D Isolated basal septal hypertrophy.
Hypertrophic cardiomyopathy: evaluation
Routine laboratory testing (include haematology, glucose, cholesterol, renal and liver function tests, electrolytes) aids the detection of extra-cardiac conditions that cause or exacerbate ventricular dysfunction and secondary organ dysfunction in patients with severe heart failure.
Genetic counselling is recommended in all patients when HCM cannot be explained solely by a non-genetic cause.
Hypertrophic cardiomyopathy: management
Patients with HCM should be advised against participation in competitive sports and discouraged from intense physical activity.
Patients with symptomatic left ventricular outflow tract obstruction are treated initially with non-vasodilating ß-blockers titrated to maximum tolerated dose.
If ß-blockers alone are ineffective, disopyramide (when available), titrated up to a maximum tolerated dose, may be added.
Verapamil can be used when ß-blockers are contraindicated or ineffective.
Diltiazem should be considered in patients who are intolerant or have contraindications to ß-blockers and verapamil.
Arterial and venous dilators, including nitrates and phosphodiesterase type 5 inhibitors, can exacerbate LVOTO and should be avoided if possible.
Digoxin should be avoided in patients with LVOTO because of its positive inotropic effects.
Hypertrophic cardiomyopathy: management
As patients with HCM tend to be younger than other high risk groups and have not
been included in clinical trials of thromboprophylaxis, use of the CHA2DS2-VASc score to calculate stroke risk is not recommended.
Given the high incidence of stroke in patients with HCM and paroxysmal, persistent or permanent AF, it is recommended that all patients with AF lifelong therapy with oral anticoagulants is recommended, even when sinus rhythm is restored.
Hypertrophic cardiomyopathy: management
Invasive treatment to reduce left ventricular outflow tract obstruction should be considered in patients with an LVOTO gradient ≥50 mm Hg, moderate-to-severe symptoms (New York Heart Association (NYHA) functional Class III–IV) and/or recurrent exertional syncope in spite of maximally tolerated drug therapy.
In some centres, invasive therapy is also considered in patients with mild symptoms (NYHA Class II) who have a resting or maximum provoked gradient of ≥50 mm Hg (exercise or Valsalva) and moderate-to-severe SAM related mitral regurgitation, AF, or moderate-to-severe left atrial dilation.
The most commonly performed surgical procedure used to treat LVOTO is ventricular septal myectomy (Morrow procedure).
In experienced centres, selective injection of alcohol into a septal perforator artery to create a localized septal scar has outcomes similar to surgery in terms of gradient reduction, symptom improvement and exercise capacity.
Restrictive cardiomyopathy
Restrictive cardiomyopathy
Restrictive cardiomyopathy (RCM) is characterized by diastolic dysfunction of a non-dilated ventricle.
The restrictive cardiomyopathies are a heterogenous group of myocardial diseases that vary according to pathogenesis, clinical presentation, diagnostic evaluation and criteria, treatment, and prognosis.
The defining feature of RCM is the coexistence of persistent restrictive pathophysiology, diastolic dysfunction, non-dilated ventricles, and atrial dilatation, regardless of ventricular wall thickness and systolic function.
Biventricular chamber size and systolic function are usually normal or nearnormal until later stages of the disease.
Restrictive cardiomyopathy
The disorders manifesting as RCM may be classified according to four main disease mechanisms:
interstitial fibrosis and intrinsic myocardial dysfunction
infiltration of extracellular spaces,
accumulation of storage material within cardiomyocytes, or endomyocardial fibrosis.
Restrictive cardiomyopathy
RCM may result from inherited or acquired predispositions and disease or a combination thereof, which broadly can be classified as infiltrative, storage disease, noninfiltrative, and endomyocardial.
Three of the leading causes of RCM include cardiac amyloidosis, cardiac sarcoidosis, and cardiac hemochromatosis.