Am Fam Physician. 1998;57(9):2071-2078
The legend for this figure reads as follows: “ECG from a 12-year-old girl with hypertrophic cardiomyopathy. Note the presence of sinus rhythm and wide, bizarre QRS complexes. The recording is at half standard, so the complexes are actually twice as large as displayed. The ECG is abnormal in over 90 percent of patients with hypertrophic cardiomyopathy. The most common abnormalities are left ventricular hypertrophy, ST-segment alterations, T-wave inversion, large Q waves and the peculiar diminution of R waves in the lateral precordial leads seen in this patient.”
Close inspection of lead V1 in this tracing shows a short PR interval, slurring of the intial portion of the QRS complex (a delta wave) and QRS widening. Although delta waves are not well seen in many of the other leads in this tracing, I believe there is slurring of the initial part of the QRS in leads V4 and V5. In addition, the multiple deflections in the inferior leads may represent partially negative delta waves. I therefore believe that this ECG is highly suggestive of Wolff-Parkinson-White (WPW) syndrome.
While I fully agree that most patients with hypertrophic cardiomyopathy have an abnormal ECG, I do not feel that the tracing shown in Figure 1 is representative of what one should expect to find with this abnormality, other than the slight increased association of a familial form of WPW that is seen with hypertrophic cardiomyopathy.
in reply: Dr. Grauer correctly points out that the ECG in Figure 1 of the second part of our review on common cardiovascular problems in the young appears to show preexcitation. The patient in question has marked septal hypertrophy and mild left ventricular outflow obstruction by echocardiography but has never complained of tachycardia. It illustrates our point that the ECG is almost always abnormal in hypertrophic cardiomyopathy, with preexcitation being one of the abnormalities that may occur.