University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

317

Pages:

2
Author:

Mariam A. A.

Dilated Cardiomyopathy Definition Enlargement of the heart muscles Epidemiology More common in men than women, 3:1 Aetiology • • • • • • • Genetic Predisposition - Mutations in the TTN gene which codes for connectin - Mutations in the MYH7 gene which codes for beta-myosin heavy chain Family history Coronary heart disease Rheumatic heart disease Alcohol use Cocaine Valvular heart disease Pathophysiology If genetic, then mutation in genes resulting in a single nucleotide being swapped, thus coding for different amino acid or if it is because of hypertension or valve disease then this acts as a compensatory mechanism -> primary/secondary hypertension -> new sarcomere added -> increased growth of the wall -> cardiomyopathy: - - Increased stiffness and decreased compliance -> takes up more space -> less space for blood -> decreased filling -> decreased stroke volume -> decreased ability to pump blood -> diastolic heart failure -> dyspnoea More oxygen needed -> ischemia -> altered heart conduction -> irregular heart beat > atrial fibrillation -> increased risk of blood clots -> brain -> stroke Asymmetrical muscle growth -> increased intraventricular septum -> gets in way of the ventricular outflow and contraction -> decreased space for blood -> pulling of anterior leaflet of mitral valve towards septum -> MVP -> murmurs Signs and Symptoms • • • • • • • • Edema Exertional Dyspnoea Ascites (due to back up of blood and fluid) Angina pectoris S3 heart sound Jugular vein distention Palpitations Systolic Murmurs Diagnosis • • • • • • Physical Exam - 3rd heart sound - Systolic murmurs - Jugular vein distension Lap test - Troponin and CK-MB to rule out MI Echocardiography - Assess for cardiac modelling - Atrial and ventricular dilation - Decreased left ventricular ejection fraction Chest X-Ray - Left-sided hypertrophy - Signs of pulmonary edema and left heart failure ECG - Finds other side effects or conductive disorders: ✓ AV block ✓ Atrial fibrillation ✓ Arrythmias ✓ Reduced QRS voltage Histology - Used to exclude causes ✓ Interstitial fibrosis ✓ Interstitial inflammation ✓ Hypertrophy ✓ Nuclear atypia Treatment • • • • Pace maker Septal Myectomy Heart rate decreasing meds - E.g., Ca2+ channel blockers Ventricular assist device