Heart Muscle Diseases (Cardiomyopathies): Test and Diagnosis

1st-order laboratory parameters-obligatory laboratory tests.

Dilated (dilated) cardiomyopathy (DCM)

  • NT-proBNP (N-terminal pro brain natriuretic peptide) – for suspected heart failure (heart weakness) Assessment: correlation between NT-proBNP and stage of heart failure/heart weakness (NYHA, median/95th percentile).
    • NYHA I: 342/3,410 ng/l
    • NYHA II: 951 / 6,567 ng/l
    • NYHA III: 1,571 / 10,449 ng/l
    • NYHA IV: 1,707 / 12,188 ng/l

    Note: Values greater than 500 ng/l /are likely to be due to heart failure. Elevated levels are reported for women on hormone replacement therapy and renal insufficiency (renal impairment)/dialysis.

  • Evidence of auto-Ak against the beta1-adrenoreceptor (approximately 75% of cases).
  • Invasive diagnostics:
    • Exclusion of ischemic cardiomyopathy (due to decreased blood flow).
    • If necessary, myocardial biopsy (tissue sample from the myocardium) and histology (fine tissue examination); especially indicated in case of a short history or a previous infection
    • Hemodynamic parameters – PA and PC pressure, LVEDP (left ventricular end-diastolic pressure).

Hypertrophic (enlarged) cardiomyopathy (HCM)

  • Myocardial biopsy-eliminable in hypertrophic obstructive cardiomyopathy (HOCM).
    • Hypertrophy and structural loss of myocytes (muscle cells) and myofibrils.
    • Interstitial fibrosis
    • Proliferation of mitochondria and widening of Z-stripes.
    • Intimal thickening of intramural coronary arteries (arteries that surround the heart in a wreath shape and supply blood to the heart muscle).
  • Genetic counseling including HCM gene panel diagnostics (genetic test consisting of the most common disease-associated genes).

Restrictive (restricted) cardiomyopathy (RCM)

  • Endomyocardial biopsy (tissue sampling from the inner layer of myocardium) with simultaneous RV/LV pressure measurement.

Arrhythmogenic right ventricular cardiomyopathy (ARVCM)

  • Possible myocardial biopsy – proliferation of intramyocardial fat cells (fibrolipomatosis).
    • Two histologic variants:
      • Fibrolipomatosis 1: predominant intramyocardial lipomatosis.
      • Fibrolipomatosis 2: predominant intramyocardial fibrosis (the left ventricle (heart chamber) may also be involved)