CLINICAL-SIGNIFICANCE OF GIANT NEGATIVE T-WAVES IN HYPERTROPHIC CARDIOMYOPATHY

To assess the clinical significance of "giant" negative T waves in patients with hypertrophic cardiomyopathy from Western nations, clinical, echocardiographic, radionuclide and 48 h electrocardiographic (ECG) monitoring findings were compared in 27 patients with and 56 patients without giant negative T waves. Patients with giant negative T waves were older at diagnosis (43 ± 15 versus 32 ± 14 years, p < 0.005), had greater ECG voltage (SV1 + RV5 = 57 ± 20 versus 37 ± 18 mm, p < 0.001) and had a more vertical frontal plane axis (38.4 ± 34 versus 13.4 ± 45 °, p < 0.05). Left ventricular wall thickness on two-dimensional echocardiography was similar at the mitral valve level (mean 16.5 ± 4 versus 16.6 ± 3 cm), but was greater at the papillary muscle level (mean 20.7 ± 5 versus 17.6 ± 3 mm, p < 0.01) and apex (mean 23.3 ± 5 versus 17.3 ± 3 mm, p < 0.001) in patients with giant negative T waves. Fewer patients with giant negative T waves had asymmetric septal hypertrophy (12 [44%] of 27 versus 36164% ] of 56, p = 0.08) or systolic anterior motion of the mitral valve (4 [14%] of 27 versus 25 [45%] of 56, p < 0.01), whereas left ventricular end-diastolic (44.1 ± 6 versus 39.6 ± 5 mm, p = 0.01) and end-systolic dimensions (27.8 ± 4 versus 24 ± 6 mm, p < 0.05) were greater in this group. Nonsustained ventricular tachycardia was seen on ECG monitoring in 21 % of patients in both groups. Radionuclide ventriculography demonstrated similar degrees of abnormal systolic and diastolic function in both groups. The outcome during follow-up study did not differ between the two groups. Reports from Japan indicate that patients with giant negative T waves have hypertrophy confined to the left ventricular apex, mild symptoms and few adverse prognostic features. This study reveals that patients in the West with giant negative T waves have a wider clinical spectrum and that their prognosis is not different from that of patients without such T waves. © 1990.