Dispersion of Filtered P Wave Duration by P Wave Signal-Averaged ECG Mapping System:

INTRODUCTION: Although it is desirable to know drug efficacy before initiating antiarrhythmic therapy, there have been no methods for this evaluation. P wave signal-averaged ECG (P-SAECG) is useful to detect subtle changes in disturbance of atrial conduction. The purpose of this present study was to test whether P-SAECG mapping system would give any information on the efficacy of disopyramide on the prevention of paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: P-SAECG was performed before disopyramide treatment, at 3 hours after a single dose of oral disopyramide (200 mg), and after 4 weeks of disopyramide treatment (300 mg/day). After measuring the filtered P wave duration by the vector magnitude and mapping methods, we calculated filtered P wave duration dispersion, difference between the maximal and minimal filtered P wave duration within 16 chest leads at these three time points. Filtered P wave duration and filtered P wave duration dispersion before treatment were longer in 32 patients with symptomatic PAF than in 31 healthy volunteers. Disopyramide was effective for suppression of PAF in 17 patients and ineffective in 15 patients after 4 weeks of treatment. Filtered P wave duration was similarly prolonged at 3 hours in the two groups, whereas filtered P wave duration dispersion at 3 hours after the disopyramide administration behaved differently; it decreased in all of the effective group and increased in all of the ineffective group. The effective patients were prospectively followed with the same treatment for 6 months. In 16 (94%) of these 17 effective patients, no PAF was documented and they remained to be asymptomatic. CONCLUSIONS: Thus, measuring filtered P wave duration dispersion with the P-SAECG mapping method after a single administration may predict the long-term efficacy of disopyramide in patients with PAF.     

Clinical Evaluation of an Immunoradiometric Assay for CA15-3 Antigen Associated With Human Mammary Carcinomas: Comparison With Carcinoembryonic Antigen

Serum levels of CA15-3, a mammary tumor associated antigen recognizedby two different murine monoclonal antibodies (115D8 and DF3),were investigated in patients with mammary carcinoma and otherbenign or malignant diseases. The reference value of the serumCA15-3 level was obtained as 24 units/ml at the 99% confidencelimit among healthy individuals (n = 462). Elevation of serumCA15-3 levels was observed in 24.3% of overall patients withmammary carcinoma. Serum CA15-3 levels in breast cancer patientscorrelated with the clinical stage; higher percentages of positivitywere observed in those with advanced breast cancer (stage IV,64.7%, recurrent, 52.4% and metastatic, 70.3%). Furthermore,elevated serum CA15-3 levels in breast cancer patients respondedwell to the effect of therapy. Although the serum CA15-3 testgave percentages of positivity of breast cancer similar to thosefound by the serum CEA test, the serum CA15-3 test revealedlower percentages of posi-tivity than the serum CEA test amongpatients with benign breast lesions, liver cirrhosis or othercarcinomas. These results suggest that the serum CA15-3 antigenlevel provides a very useful marker for diagnosis and clinicalmonitoring of patients with breast cancer.     

Diastolic Mitral Regurgitation in Patients with First-Degree Atrioventricular Block

Diastolic mitral regurgitation has been observed in patients with DDD pacemakers when the atrioventricular (AV) delay was prolonged. However, diastolic mitral regurgitation associated with first-degree AV block has not been fully studied. We examined transmitral blood flow in 24 patients with first-degree AV block and normal cardiac function (ages 35.3 ± 17.4 years), and in nine patients with DDD pacemakers and normal cardiac function (ages 73.1 ± 8.1 years), using pulsed Doppler echocardiography. Diastolic mitral regurgitation was observed in 19 of 24 patients with first-degree AV block. Although PQ interval was shortened from 0.32 ± 0.06 to 0.20 ± 0.05 seconds (P < 0.01) after 1 mg atropine sulfate IV, the interval between P wave (ECG) and the beginning of diastolic mitral regurgitation did not change, while the duration of diastolic mitral regurgitation was shortened from 0.15 ± 0.03 to 0.05 ± 0.03 seconds (P < 0.01). There was a significant correlation between changes in PQ interval and changes in the duration of diastolic mitral regurgifation (r = 0.92, P < 0.001). Although cardiac output (3.9 ± 0.05 L/min) and pulmonary capillary wedge pressure (5.1 ± 1.5 mmHg) were normal in all patients with pacemakers, diastolic mitral regurgitation was observed when the AV delay was prolonged. The critical PQ interval for the appearance of diastolic mitral regurgitation was 0.23 ± 0.01 seconds. In patients with prolonged PQ intervals, delayed ventricular contraction following atrial contraction may be associated with mitral regurgitation in the presence of a reversed AV pressure gradient. The results of this study suggest that diastolic mitral regurgitation occurs not only in patients with DDD pacemakers, but also with AAIR pacemakers when the PQ interval is prolonged. The occurrence of diastolic mitral regurgitation is associated with the pacing mode or the setting of AV delay.     

Multivariate autoregressive analysis of carotid artery blood flow waveform in an infant of a diabetic mother with cardiomyopathy

We analyzed the carotid artery blood flow waveform (CABFW) of an infant of a non-insulin dependent diabetic mother with hypertrophic cardiomyopathy (IDM cardiomyopathy) through multivariate autoregressive analysis and compared the developmental change of his CABFW with that of normal newborns. The total power was lower than normal newborns on the second and third day of life when his heart dysfunction was severe, and elevated on the fifth day of life when normal-heart function was recovered. The power of component 3 (C3), of which the damping frequency was 7–11 Hz, was slightly high on the second and third day of life and it decreased to the normal range on the fifth day of life by component analysis. In contrast, the power of C3 increased with decreasing resistance index of anterior cerebral artery (RI of ACA) which shows the cerebral vascular resistance of normal newborns. These results suggest that the carotid artery blood flow volume decreased by low cardiac output and the cerebral vascular resistance decreased to maintain the cerebral circulation, when the heart dysfunction was severe.     

Renoprotective effects of asialoerythropoietin in diabetic mice against ischaemia–reperfusion-induced acute kidney injury

Aim: Diabetic patients are at higher risk of failure to recover after acute kidney injury, however, the mechanism and therapeutic strategies remain unclear. Erythropoietin is cytoprotective in a variety of non‐haematopoietic cells. The aim of the present study was to clarify the mechanism of diabetes‐related acceleration of renal damage after ischaemia–reperfusion injury and to examine the therapeutic potential of asialoerythropoietin, a non‐haematopoietic erythropoietin derivative, against ischaemia–reperfusion‐induced acute kidney injury in diabetic mice. Methods: C57BL/6J mice with and without streptozotocin‐induced diabetes were subjected to 30 min unilateral renal ischaemia–reperfusion injury at 1 week after induction of diabetes. They were divided into four group: (i) non‐diabetic plus ischaemia–reperfusion injury; (ii) non‐diabetic plus ischaemia–reperfusion injury plus asialoerythropoietin (3000 IU/kg bodyweight); (iii) diabetic plus ischaemia–reperfusion injury; and (iv) diabetic plus ischemia–reperfusion injury plus asialoerythropoietin. Experiments were conducted at the indicated time periods after ischaemia–reperfusion injury. Results: Ischaemia–reperfusion injury of diabetic kidney resulted in significantly low protein expression levels of bcl‐2, an anti‐apoptotic molecule, and bone morphogenetic protein‐7 (BMP‐7), an anti‐fibrotic and pro‐regenerative factor, compared with non‐diabetic kidneys. Diabetic kidney subsequently showed severe damage including increased tubular cell apoptosis, tubulointerstitial fibrosis and decreased tubular proliferation, compared with non‐diabetic kidney. Treatment with asialoerythropoietin induced bcl‐2 and BMP‐7 expression in diabetic kidney and decreased tubular cell apoptosis, tubulointerstitial fibrosis and accelerated tubular proliferation. Conclusion: Reduced induction bcl‐2 and BMP‐7 may play a role in the acceleration of renal damage after ischaemia–reperfusion injury in diabetic kidney. The renoprotective effects of asialoerythropoietin on acute kidney injury may be mediated through the induction of bcl‐2 and BMP‐7.     

Developmental change in carotid artery blood flow waveform by component analysis in children

The carotid artery blood flow waveform (CABFW) is regarded as a summation of cardiac impulse responses. These impulse responses are divided into several components through a two-dimensional autoregressive modelling approach. Using this approach, we determined the developmental change in CABFW in 94 normal subjects from the neonatal period to adolescence. Our analysis demonstrated that: (i) the total power of impulse response increased significantly with increasing age. The component of impulse response was divided into six groups according to the damping frequency: group I (0 Hz), group II (1–5 Hz), group III (5–8 Hz), group IV (8–13 Hz), group V (13–17 Hz) and group VI (> 17 Hz); (ii) the power-density and the damping time of group I and II impulse response increased significantly with increasing age; (iii) the power-density and percent power of group III impulse response and power-density of group IV impulse response increased significantly with increasing age. Our results indicated that CABFW contained some regular impulses and that group I, II, III and IV, which were influenced by several factors, including cardiac contraction and the compliance and frictional forces of the carotid artery, appeared to be important to the developmental change of CABFW in children.     

Necrotizing fasciitis resulting from Escherichia coli in a patient with chronic rheumatoid arthritis

A middle‐aged woman with rheumatoid arthritis was admitted because of cellulitis on the leg. Twenty‐four hours after admission haemorrhagic blisters and bullae appeared on the lower extremity. Despite intensive therapy she died due to multiple organ failure at 50 h after admission. Post‐mortem examination revealed diffuse necrosis of fascia in her leg. Bacteriological study showed Escherichia coli in her blood cultures and fluid from a bulla, indicating that she had necrotizing fasciitis resulting from Escherichia coli. Necrotizing fasciitis is an uncommon but potentially fatal infection; thus, this disease should be considered in the differential diagnosis of any cutaneous manifestations in patients with rheumatoid arthritis.