Left ventricular hypertrophy (LVH) is a condition in which there is an increase in left ventricular mass, either due to an increase in wall thickness or due to left ventricular cavity enlargement, or both. Most commonly, the left ventricular wall thickening occurs in response to pressure overload, and chamber dilatation occurs in response to the volume overload.¹
Diagnostic criteria for a left ventricular hypertrophy (LVH)
- ↑ QRS voltage in standard leads: R in I + S in III ≥ 25 mm
- ↑ praecordial voltage: S in V1 + R in V5/V6 ≥ 35 mm
- ST segment + T-wave abnormality
- Left atrial abnormality
LVH is compensatory but ultimately an abnormal increase in the mass of the myocardium of the left ventricle, induced by a chronically elevated workload on the heart muscle. But once developed, pathologic LVH significantly increases the risk for the development of heart failure, dysrhythmias, and sudden death. The most common etiologic cause is the heart contracting against an elevated afterload, as seen in hypertension and also seen in valvar aortic stenosis. Another cause is increased filling of the left ventricle inducing diastolic overload, which is the underlying mechanism for eccentric LVH in patients with regurgitant valvular lesions such as aortic regurgitation or mitral regurgitation and also seen in dilated cardiomyopathy. Coronary artery disease has been demonstrated to play a role in the pathogenesis of LVH, as the normal myocardium tries to compensate for tissue that has become ischemic or infarcted. One key pathophysiologic component in LVH is the concomitant development of myocardial fibrosis. Initially, fibrosis is clinically manifested by diastolic dysfunction, but systolic dysfunction will also develop with progressive disease.¹
References
- Bornstein AB, Rao SS, Marwaha K. Left Ventricular Hypertrophy. [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557534/.
