No abstract

SUMMARYNormal P wave signal-averaged electrocardiogram (SAE) values were determined in 120 healthy Japanese adults (56 men, 64 women), aged 44.5±10.2 years (mean±SD). The P wave trigger method was used with a Fukuda FDX6500 recorder. We used bipolar Weak positive correlations were observed between fPd (F) and body surface area, fPd (F) and age, fPd (B) and body surface area, fPd (B) and age, fPd (C) and body surface area, and fPd (C) and age. There was no evident correlation, however, between either forward or backward RMS 20 and body surface area or between forward or backward RMS 20 and age. Differences in the normal P wave values between the sexes and age groups were evaluated in this study. (Jpn Heart J 2001; 42: 295-305) Key words: Signal-averaged P wave electrocardiogram, Japanese, Sex, Age ATRIAL late potential studies of P wave recordings by signal-averaged electrocardiography (SAE) have recognized the utility for identifying patients at risk for paroxysmal atrial fibrillation (Paf) during sinus rhythm.1,2) With Paf, filtered P duration (fPd) is long, the last 20-ms root mean square voltage (RMS 20 ) is reported to be low, and the occurrence of Paf can be predicted by such values during sinus rhythm. However, there have been no reports of normal P wave SAE values in Japan.We conducted a study in healthy Japanese subjects to determine the normal value of P waves SAE and to investigate age and sex differences. We expected a From the

SUMMARYA surgically-treated case of left atrial myxoma complicating congenital coronary artery fistula is reported. A review of the literature indicates that this complication has not been reported previously. (Jpn Heart J 36: 825-828, 1995) Key words:Cardiac myxoma Congenital coronary artery fistula Angiographically visible neovascularity Lake-like pooling C ORONARY artery fistula (CAF) has been considered to be a rare anomaly; its incidence was 0.17% in 126,595 patients undergoing coronary arteriography (CAG) during the period of 1960 to 1988.1) Recent advances in CAG and the more widespread adoption of this technique are reportedly related to the increased frequency of detection of CAF. The incidence of primary tumors of the heart in autopsy cases ranges from 0.0017 to 0.28%, and myxomas are the most common type of primary cardiac tumor, comprising 30 to 50% of the total in most studies.2) Recent progress in echocardiography is also linked to the easier diagnosis of myxoma. The prevalence of angiographically visible neovascularity in patients with myxoma is reported to be 40%.3) Our review of the literature, however, failed to uncover a single case of CAF complicated by cardiac myxoma. CASE REPORTA 51 year-old female was admitted to our hospital for the further evaluation of palpitations, dyspnea, and chest discomfort. She had noted these symptoms for the previous 6 years, but she had not received any medication. Because both the duration and frequency of the episodes had increased, she consulted our hospital in May 1988.

Signal-averaged (SA) electrocardiography and SA electrocardiographic mapping were performed in 50 patients with old myocardial infarction, 19 of whom had left ventricular aneurysm and 11 of whom had clinical sustained ventricular tachycardia. The SA electrocardiogram and SA electrocardiographic mapping data were then compared with those obtained by endocardial catheter mapping in patients with or without fragmented electrograms, sustained ventricular tachycardia, and ventricular aneurysm. Compared to SA electrocardiography, the SA map correlates with sustained VT with improved sensitivity but decreased specificity. However, SA electrocardiographic mapping had the advantage of displaying the extent of the body surface area that was positive for late potentials. In addition, the site of the longest endocardial fragmented electrogram could be predicted by SA electrocardiographic mapping, suggesting that this technique deserves wider clinical application.

We compared signal-averaged electrocardiography (SAE), SAE mapping, and left ventricular catheter mapping in 60 patients with ischemic heart disease. Using the data obtained in patients with no fragmented electrograms (FE) in the left ventricle, the late potential was defined by SAE as a filtered QRS duration > 131 msec or a root mean square voltage < 16 microV for the last 40 msec of the QRS complex. SAE mapping was performed by recording the signal-averaged electrocardiogram at 48 sites on the body surface. With SAE mapping, the filtered QRS duration and the area in the last 20 msec of the QRS complex were significantly different between the patients with and without FEs. The late potential was defined by SAE mapping as a filtered QRS duration > 136 msec or an area < 28 microV.msec for the last 20 msec of the QRS complex. The sensitivity and specificity of detecting FEs were 46% and 88%, respectively, by the SAE filtered QRS criterion, while they were 66% and 88% by the root mean square criterion. In contrast, SAE mapping gave values of 66% and 92% by the filtered QRS criterion, as well as values of 100% and 92% by the area criterion. Thus, SAE mapping provided better detection of the FE and was more closely correlated with the results of catheter mapping, suggesting its potential for clinical application.