Clinical and Echocardiographic Evaluation of Regional Systolic Function Detected by Tissue Doppler Imaging in Hypertrophic Cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is the most common type of the genetic cardiovascular diseases. Regarding to tremendous heterogeneity in the phenotypic expression of HCM, which is generally unrelated to genotype, we aimed to study, clinical and echocardiographic parameters such as Tissue Doppler Imaging (TDI) in various subtypes of HCM patients and evaluate the influence of race and gender in Iranian patients. Methods: Patients with HCM underwent a complete clinical and echocardiographic study including TDI to assess regional systolic contraction(in the 12 segments) and early diastolic annular velocity (Em) from the septal mitral annulus. Results: The study comprised 41 patients (20 women, mean age = 41 +/- 15 years) with mean LVEF 55%+/- 4.8% and mean maximal septal thickness 2.07cm. Considering LVOT gradient>30mmHg, hypertrophic obstructive cardiomyopathy (HOCM) was found in 18 (45%). Asymmetric septal hypertrophy (ASH) existed in 27 patients (67%), systolic anterior motion of anterior mitral leaflet (SAM) in 25 persons (64%). Nineteen patients (46.3%) were included in NYHA function class (FC) II and 6 (14.7%) in FC III or higher. We found syncope in 10 (24.4%), chest pain in 4 (9.8%), atrial fibrilation in 14.6 % and ventricular arrhythmias in (17.1%) of patients. History of ICD was seen in 7 (17.1%) and PPM in 9 cases. Mean E' velocity was 5.44 +/- 1.65 cm/sec and S velocity 5.70 +/- 1.49 cm/sec with significant lower S velocity and E' in syncope patients. Overall, HOCM patients had grade II diastolic dysfunction with E/E >15(17.54 +/- 7.46). Majority (25) of cases (61%) were categorized in type III of HCM. RV involvement was observed in 11 patients (28.2%). No significant differences existed between prevalence of syncope and dysrhythmia among HCM and HOCM patients. Conclusion: In our study, we found lower detection of latent HOCM, compared to other studies, suggestive of inadequate use of appropriate provocative maneuvers such as exercise stress echocardiography and amyl nitrate. We detected remarkably lower S velocity (5.70 +/- 1.49 cm/sec) and E' velocity (5.44 +/- 1.65 cm/sec) in HCM patients compared to normal subjects, with more significant reductions in patients with syncope.