Hypertrophic cardiomyopathy: Can the noninvasive diagnostic testing identify high risk patients?

Abstract

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death (SCD) in the young, particularly among athletes. Identifying high risk individuals is very important for SCD prevention. The purpose of this review is to stress that noninvasive diagnostic testing is important for risk assessment. Extreme left ventricular hypertrophy and documented ventricular tachycardia and fibrillation increase the risk of SCD. Fragmented QRS and T wave inversion in multiple leads are more common in high risk patients. Cardiac magnetic resonance imaging provides complete visualization of the left ventricular chamber, allowing precise localization of the distribution of hypertrophy and measurement of wall thickness and cardiac mass. Moreover, with late gadolinium enhancement, patchy myocardial fibrosis within the area of hypertrophy can be detected, which is also helpful in risk stratification. Genetic testing is encouraged in all cases, especially in those with a family history of HCM and SCD.

Comparison of clinical and echocardiographic parameters in patients with hypertrophic cardiomyopathy under and over 60 years of age

“…LVEF in persons with HCM is usually preserved or increased when compared with the healthy population [26]. Our study confirms that the median value of LVEF in both age subgroups was >50% (the lower limit of normal range) ( Table 2).…”

Assessment of the association between the presence of fragmented QRS and the predicted risk score of sudden cardiac death at 5 years in patients with hypertrophic cardiomyopathy

“…Inhomogeneous activation of the ventricles because of partially depolarized and depressed action potential upstroke velocities due to regional slow activation of the islands of chronically ischemic ventricular myocardium manifests itself as fQRS on 12-lead ECG ( 13 , 14 ). Actually, fractionated ECGs consisting of multiple discrete deflections have been observed in regions where “islands” of viable myocardial tissue are interspersed with abundant fibrous tissue ( 15 ).…”

Cardiac Magnetic Resonance and Computed Tomography in Hypertrophic Cardiomyopathy: an Update

“… 10 However, the measurement of LV mass lacks specificity as an indicator of clinical outcomes, probably because in many HCM patients, hypertrophy is limited to a small number of segments of the left ventricle. 29 …”