Shintaro Tanihata

Identification of asynergic but viable myocardium in patients with chronic coronary artery disease by gated blood pool scintigraphy during isosorbide dinitrate and low-dose dobutamine infusion: Comparison with thallium-201 scintigraphy with reinjection

To evaluate the ability of low-dose dobutamine and isosorbite dinitrate (ISDN) gated blood pool scintigraphy (GBPS) and thallium SPECT with reinjection to identify viability in asynergic myocardium, both procedures were performed in 38 consecutive patients with chronic coronary artery disease and left ventricular dysfunction. Twenty-two of the 38 patients with successful revascularization were analyzed. GBPS was performed at the baseline and during continuous infusion of low dose dobutamine (5 μg/kg/min) and ISDN (2 μg/kg/min). Cine mode GBPS wall motion was scored from normal (0) to dyskinesis (4) semiquantitatively. Forty-seven of 110 segments with severe asynergy at the baseline were analyzed. Viability determined by GBPS was defined as wall motion score improvement by more than 1 grade. Thallium viability was defined as the segment with redistribution or fill in with severe initial perfusion defect. GBPS was 76.7% sensitive and 70.6% specific for predicting post vascularization wall motion improvement (p < 0.005). Of 47 segments with severe asynergy, concordance of judgement was obtained in 40 segments (85.1 %), and reversibility was correctly diagnosed in 34 of 40 patients (85.0%), but thallium with reinjection correctly identified tissue viability in 6 of 7 segments with discordance between 2 studies.These data suggest that most cases of reversible asynergy (hibernating myocardium) respond to ISDN and dobutamine, suggesting the possibility of predicting improvement by revascularization, although some underestimation of tissue viability remained to be resolved. Thallium with reinjection is superior to low-dose dobutamine + ISDN GBPS for the assessment of myocardial viability.

LEFT ATRIAL STRUCTURE AND FUNCTION IN HYPERTENSIVE PATIENTS ASSESSED BY REAL-TIME THREE-DIMENSIONAL SPECKLE TRACKING ECHOCARDIOGRAPHY: A COMPARATIVE STUDY WITH NORMAL SUBJECTS AND TWO-DIMENSIONAL SPECKLE TRACKING

Major advantage of 3-dimensional speckle tracking echocardiography (3-DSTE) is the improvement of accuracy in the evaluation of cardiac chamber volume without any geometrical assumption. However, there have been few studies regarding to left atrial (LA) structure and function using 3-DSTE. The aim

LEFT ATRIAL PHASIC FUNCTION ASSESSED BY SPECKLE TRACKING ECHOCARDIOGRAPHY IS A USEFUL PREDICTOR FOR FIRST ATRIAL FIBRILLATION: RESULTS OF PROSPECTIVE STUDY OF 2 YEARS FOLLOW-UP

Methods: LA total, passive and active emptying function (EF) as a global function and LA strain rate (SR) at systole, early diastole and atrial contraction as a regional function were measured in apical 4-chamber view by speckle tracking in consecutive 420 adults without mitral valve disease and atrial arrhythmia (age 68±14, 251 men). LA volume, left ventricular (LV) mass, ejection fraction, and E/e’ as a diastolic function were measured.

Evidence of pharmacologic preconditioning during PTCA by intravenous pre-treatment of ATP-sensitive K+ channel opener NICORANDIL

BACKGROUND It is not known whether pretreatment with nicorandil, an ATP-sensitive K+ channel (K(ATP)channel) opener, induces a preconditioning effect independent of increased collateral recruitment. METHODS Forty-four patients with angina who underwent percutaneous transluminal coronary angioplasty (PTCA) to proximal left anterior descending artery (LAD) stenosis were randomly allocated for pretreatment with an intravenous injection of 80 g/kg nicorandil 5 min before initial ballooning (n=22) or saline (n=22). 99mTc tetrofosmin was injected during balloon inflation, quantitative analysis of occlusion images by SPECT was conducted, and the defect severity score (SS) was calculated. An ECG was recorded during the 2-min inflation to calculate the sum of ST elevation (sigmaST). RESULTS SigmaST levels were significantly reduced in patients with nicorandil pretreatment compared with control patients (control:1.89+/-0.85 mV nicorandil:1.24+/-0.57 mV, p=0.0052). However, no difference was observed in defect severity (control: 79.0+/-32.5, nicorandil: 98.7+/-48.9 ns). A close correlation was observed between SS and sigmaST in both groups (nicorandil group R(2)=0.505, control group R(2)=0.599). A multivariate regression model demonstrated that both defect severity (p<0.0001) and pretreatment with nicorandil (p<0.001) were significantly related to the level of sigmaST, suggesting a cellular protective effect against ischaemia by nicorandil, independent of myocardial blood flow. CONCLUSION Nicorandil pretreatment resulted in the induction of myocardial preconditioning independent of the severity of ischaemia.