Isointegral Analysis of Body Surface Electrocardiographic Mapping for Assessing Exercise-Induced Changes in Repolarization Properties in Patients with Coronary Artery Disease

To assess the exercise-induced changes in repolarization properties in patients with coronary artery disease, we analyzed body surface ECG mapping. The patients studied had a normal resting 12-lead ECG and were divided into 2 groups: group A (n = 15; coronary artery narrowing [?], exercise thallium defect [?], ST depression 0.1 mV [?]) and group B (n = 17; [+], [+], [+]). All patients in group B showed significant area (< ?10 ?V?s) in the postexercise ST-T isointegral map. Of the patients in group B, 10 (59%) showed significant area in the postexercise QRST isointegral map and 15 (88%) showed “?2SD area (less than mean ?2SD values in group A)” in the difference map between resting and postexercise QRST isointegrals. The correlation coefficient between resting and postexercise QRST isointegrals in 87 lead points was significantly lower in group B (0.28 ± 0.56) than in group A (0.91 ± 0.06, P < 0.001). Our results indicate that patients with ischemic ST depression have a greater decrease in the QRST isointegral values in the precordial region than patients without ischemia and ST depression. There are also low similarities between resting and postexercise QRST isointegral maps. We conclude that ischemic ST depression is related to the dispersion of the exercise-induced changes in repolarization properties

Enhancing effects of salicylate on tonic and phasic block of Na+ channels by class 1 antiarrhythmic agents in the ventricular myocytes and the guinea pig papillary muscle

AbstractObjective: To study the interaction between salicylate and class 1 antiarrhythmic agents. Methods: The effects of salicylate on class 1 antiarrhythmic agent-induced tonic and phasic block of the Na+ current (INa) of ventricular myocytes and the upstroke velocity of the action potential (Vmax) of papillary muscles were examined by both the patch clamp technique and conventional microelectrode techniques. Results: Salicylate enhanced quinidine-induced tonic and phasic block of INa at a holding potential of −100 mV but not at a holding potential of −140 mV; this enhancement was accompanied by a shift of the h∞ curve in the presence of quinidine in a further hyperpolarized direction, although salicylate alone did not affect INa. Salicylate enhanced the tonic and phasic block of Vmax induced by quinidine, aprindine and disopyramide but had little effect on that induced by procainamide or mexiletine; the enhancing effects were related to the liposolubility of the drugs. Conclusions: Salicylate enhanced tonic and phasic block of Na+ channels induced by class 1 highly liposoluble antiarrhythmic agents. Based on the modulated receptor hypothesis, it is probable that this enhancement was mediated by an increase in the affinity of Na+ channel blockers with high lipid solubility to the inactivated state channels

Screening Criteria of Diabetes Mellitus and Impaired Glucose Tolerance of the Japanese Population in a Rural Area of Japan: The Tottori-Kofu Study

We performed the Tottori-Kofu Study to develop an early detection method of the Japanese with diabetes mellitus (DM) and impaired glucose tolerance (IGT), using simple predictors such as fasting plasma glucose (FPG) and other risk information obtainable from basic medical check-ups. In 2005, 734 residents of Kofu Town received a basic medical check-up including blood examination. Some of them meeting the following criteria further underwent the oral glucose tolerance test (OGTT): 5.5 mmol/L (100 mg/dL) ? FPG < 7.0 mmol/L (126 mg/dL); or FPG < 5.5 mmol/L, HbA1c ? 5.5%, BMI ? 25 kg/m2, triglyceride ? 1.69 mmol/L (150 mg/dL), hypertension treatment and family history of DM. Among the 734, only 4 persons with FPG ? 7.0 mmol/L were newly diagnosed as having DM, and 17 persons with FPG ? 6.1 mmol/L (110 mg/dL) were diagnosed with impaired fasting glucose. Among 220 persons who received the OGTT, 115 had normal glucose tolerance, 85 had IGT and 20 had DM. When the above-mentioned criteria were added to FPG levels, additional 67 persons with abnormal glucose tolerance were found. The optimal level to detect IGT and DM was 5.2 mmol/L (93 mg/dL) for FPG and 5.3% for HbA1c. Of persons only with the single risk factor of hypertension treatment, 39.3% had IGT. In conclusion, the results indicate that FPG of 5.2 mmol/L (93 mg/dL), HbA1c of 5.3% and hypertension treatment are useful in detecting early stages of IGT and DM

Screening Criteria of Diabetes Mellitus and Impaired Glucose Tolerance of the Japanese Population in a Rural Area of Japan: The Tottori-Kofu Study

We performed the Tottori-Kofu Study to develop an early detection method of the Japanese with diabetes mellitus (DM) and impaired glucose tolerance (IGT), using simple predictors such as fasting plasma glucose (FPG) and other risk information obtainable from basic medical check-ups. In 2005, 734 residents of Kofu Town received a basic medical check-up including blood examination. Some of them meeting the following criteria further underwent the oral glucose tolerance test (OGTT): 5.5 mmol/L (100 mg/dL) ? FPG < 7.0 mmol/L (126 mg/dL); or FPG < 5.5 mmol/L, HbA1c ? 5.5%, BMI ? 25 kg/m2, triglyceride ? 1.69 mmol/L (150 mg/dL), hypertension treatment and family history of DM. Among the 734, only 4 persons with FPG ? 7.0 mmol/L were newly diagnosed as having DM, and 17 persons with FPG ? 6.1 mmol/L (110 mg/dL) were diagnosed with impaired fasting glucose. Among 220 persons who received the OGTT, 115 had normal glucose tolerance, 85 had IGT and 20 had DM. When the above-mentioned criteria were added to FPG levels, additional 67 persons with abnormal glucose tolerance were found. The optimal level to detect IGT and DM was 5.2 mmol/L (93 mg/dL) for FPG and 5.3% for HbA1c. Of persons only with the single risk factor of hypertension treatment, 39.3% had IGT. In conclusion, the results indicate that FPG of 5.2 mmol/L (93 mg/dL), HbA1c of 5.3% and hypertension treatment are useful in detecting early stages of IGT and DM