Age and sex differences in the P-wave signal-averaged electrocardiogram in a Japanese study population.

Normal 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 Frank leads (X,Y,Z), and recordings were made with forward and backward digital Butterworth filters [40 Hz (18 dB / oct) - 300 Hz (12 dB / oct)]. The recordings were taken for the following five parameters: forward and backward filtered P wave duration [fPd (F); tPd (B)]; bidirectionally corrected fPd [tPd (C)]; and 20 ms of the terminal portions of voltage at forward and backward filtering (RMS20). Overall, fPd (F) was 117.8-136.4 ms, fPd (B) 116.4-134.4 ms, fPd (C) 97.4-115.2 ms, RMS20 (F) 1.6-3.6 microV, and RMS20 (B) was 2.2-5.4 microV. Between the sexes, there were significant differences in fPd (F) (p<0.001) and fPd (B) (p<0.01) and in RMS20 (F) (p<0.05) and RMS20 (B) (p<0.05). 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 RMS20 and body surface area or between forward or backward RMS20 and age. Differences in the normal P wave values between the sexes and age groups were evaluated in this study.

A surgically-treated case of left atrial myxoma complicating coronary artery fistula.

A surgically-treated case of left atrial myxoma complicating congenital coronary fistula is reported. A review of the literature indicates that this complication has not been reported previously.

A surgically treated case of both Wolff-Parkinson-White syndrome and atrial septal defect complicating single coronary artery and partial pericardial defect.

A surgically treated case of both Wolff-Parkinson White syndrome and atrial septal defect complicating a single coronary artery and partial pericardial defect is reported. These complications are very rare. In addition, the accessory pathway of this case had unique decremental conduction characteristics.

Endocardial fragmented electrogram and prediction of ventricular tachycardia by body surface signal-averaged electrocardiographic mapping.

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.

[Establishment of signal-averaged electrocardiographic system and system specific criteria].

Signal-averaging of high resolution electrocardiographic data to identify ventricular late potentials, associated with ventricular tachycardia, has emerged as a useful technique for risk stratification following myocardial infarction. Multiple lead system, filters and criteria have been used in clinical trials. As variations in data analysis are introduced, it is important to assess the impact of the final results and to ensure that criteria for normalcy, appropriate for these variation, are developed if needed. This study compares the results produced by four systems and one system with a different filter used for determination of late potential parameters in the time domain. It is concluded that varying technique and filters significant changes in the values used to identify late potentials on high-resolution electrocardiographic records. These change may have clinical impact. When using this technique in a clinical situation, parameters values, appropriate for the device, and its components should be developed, if needed.

[Noninvasive technique for detection of electrical activity from the region of the bundle of His using by signal-averaged electrocardiographic system].

Recently, signal-averaging technique of high resolution electrocardiogram to detect electrical activity from the region of the bundle of His has developed. But this technique has not been commonly used for detection of His bundle activity, compare it with detection of late potentials. We studied suitable lead system, filters, signal averaging counts and high resolution gain to detect surface recording of His bundle activity. We also studied that if we recorded electrogram using late potential detection system, how many people could be detected for His bundle activity. Signal-averaging technique of high resolution electrocardiogram clinically applicated especially in atrio-ventricular block patients. There were significant changes in the frequency of identifying His bundle activity by signal-averaging electrocardiographic system recorded by varying leads system, filters, averaging counts, high resolution gain. When using this technique in a clinical situation, we should use most appropriate device, including its condition.

Correlation of the endocardial fragmented electrogram with body surface signal-averaged electrocardiographic mapping.

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.

[A case of an unusual type of coarctation of the aorta terminating in the complete obstruction].

A 19 year-old girl with an unusual type of coarctation of the aorta terminating in complete obstruction is presented. At the age of 5 years, she was diagnosed by aortography to have coarctation of the aorta of type IV C according to Edward's classification. No surgical treatment was performed at that time because her growth was good and she didn't have hypertension. During the follow-up period, marked hypertension developed, and she was readmitted. The aortogram revealed a bicuspid aortic valve and total obstruction of the descending thoracic aorta at the site where coarctation was noticed previously. The abdominal aorta distal from the obstruction site was filled through rich collateral circulation. As these angiographic interval changes are very rare, we discussed the genesis of obstruction and operative indication by reviewing the literature.

Infective endocarditis causing acute myocardial infarction by compression of the proximal left coronary artery due to a mycotic aneurysm of the sinus of Valsalva.

An extremely unusual case of myocardial infarction associated with infective endocarditis (IE) is described. A 38-year old male with a high fever was transferred to our hospital for further treatment of IE. Two-dimensional echocardiogram showed a large mycotic aneurysm of the sinus of Valsalva in contact with neighbouring structures. The patient had a rapid recovery within several days after administration of antibiotic agents. However, he then developed abrupt onset of severe precordial pain. From the echocardiogram images and biochemical evaluation he was diagnosed as having an acute subendocardial infarction. Serial echocardiograms revealed expansion of the aneurysm, extending from the myocardium of the anterolateral free wall to the lower margin of the proximal left coronary artery. The cause of acute myocardial infarction was thought to be incomplete occlusion of the coronary artery through compression by the enlarging mycotic aneurysm of the sinus of Valsalva. Urgent surgery confirmed compression of the left coronary artery by the large mycotic aneurysm as the cause of acute myocardial infarction.

[A case of pulmonary arteriovenous fistula accompanied with marked polycythaemia].

A 67-year-old male was admitted with cyanosis, digital clubbing and exertional dyspnea. Laboratory data revealed severe polycythaemia with 26 mg/dl hemoglobin, red blood cell; 866 x 10(-4)/mm3, hematocrit 72.8% and PaO2 44.6 mmHg. Selective pulmonary angiography demonstrated a large arteriovenous fistula involving the right middle lobe. After venesection of 1,200 ml of blood, the middle lobectomy was performed safely. In a case of pulmonary arteriovenous fistula with such severe polycythaemia, preoperative venesection is useful to decrease perioperative complications.

[Patients resuscitated from cardiopulmonary arrest: clinical and electrophysiologic study].

Clinical and electrophysiologic studies (EPS) were carried out in 12 patients who were resuscitated from cardiopulmonary arrest (CPA). They were 8 males and 4 females, ranging from 33 to 73 years of age with a mean of 55 years. Underlying diseases included old myocardial infarction (OMI) with aneurysm (An) in 6 patients, variant angina, arrhythmogenic right ventricular dysplasia, Romano-Ward syndrome, complete atrioventricular block in one each, and diseases of unknown etiology in 2. Ergonovine-provocative coronary angiography (CAG) was performed in 3 patients, and EPS including ventricular tachycardia study was performed in 7. Coronary artery spasm was induced in one patient during CAG; sustained monomorphic ventricular tachycardia in 4 patients; and repetitive ventricular response in 2 of 7 patients examined by EPS. The causes of cardiopulmonary arrest were clearly demonstrated by the above-described examinations in 3 cases of clinically unidentified etiology. Drug therapy was performed in 6 patients during EPS (1.7 drugs/case), which was effective in one, ineffective in 3, and undetermined in 2. Of 2 patients whose surgical treatment was unsuccessful, atrial pacing with propranolol administration was used in a patient with Romano-Ward syndrome. The remaining patients were followed up medically. Cardiopulmonary arrest recurred in 3 patients and resuscitation was not successful in any of them; one with OMI and the other 2 with idiopathic ventricular fibrillation who refused EPS and died suddenly 10 months and 12 months after their initial resuscitation. Cardiac arrest did not recur in any of those who underwent complete examinations and were treated with medications, however, it recurred in 3 of 5 patients without complete medications. As a whole, cardiopulmonary arrest recurred in 3 of 12 patients (25%) within one year after the onset of symptoms. To reduce the possibility of the recurrence of arrest and improve prognosis in patients with previous successful cardiac resuscitation, intensive examinations for the causes, therapy including EPS and ergonovine CAG, full medications and surgical treatment may be helpful.