Điện chính của phì đại tâm thất thường cho thấy phì đại tâm thất trái, nhưng có thể cho thấy phì đại tâm thất phải hoặc kết hợp, nó có thể không thể phân biệt điện của phì đại thứ cấp do tình trạng quá tải huyết áp tâm thu từ phì đại tâm thất chính. | 197 and anteriorly. This produces extremely large and inverted T waves in leads I II III V4 V5 and Vs and is more likely to occur when there is apical hypertrophic cardiomyopathy. reliable sign of right ventricular hypertrophy. Table Electrocardiographic Abnormalities That Must Be Differentiated From Those Due to Primary Ventricular Hypertrophy The electrocardiogram of primary ventricular hypertrophy usually shows left ventricular hypertrophy but may show right or combined ventricular hypertrophy as well it may not be possible to distinguish the electrocardiogram of secondary hypertrophy due to systolic pressure overload from that of primary ventricular hypertrophy. The electrocardiogram of myocardial infarction may simulate that of primary ventricular hypertrophy. The following distinctions apply When due to myocardial infarction the abnormal initial QRS forces ST segment and T wave abnormalities usually evolve through a set of stages but these features rarely change when they are due to primary hypertrophy. Electrocardiographic signs of left ventricular hypertrophy ie an increase in QRS amplitude rarely occur with myocardial infarction unless there is associated systemic hypertension aortic valve disease or mitral regurgitation. Signs of left ventricular hypertrophy are often present when the pseudoinfarction pattern is due to hypertrophic cardiomyopathy. There are many causes for an abnormal mean T vector left ventricular ischemia left ventricular hypertrophy pericarditis or subarachnoid hemorrhage among others. When due to apical hypertrophy the large mean T vector is directed to the right and anteriorly. The electrocardiographic abnormalities associated with the Wolff-Parkinson-White syndrome may occur with primary ventricular hypertrophy. It is not possible to distinguish the signs of isolated bypass tracts from those associated with primary hypertrophy. When signs of a bypass tract are identified one must search for the clues to primary ventricular .
