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A 54-year-old woman was hospitalized in 1989 because of palpitations. She had a family history of hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy was diagnosed by two-dimensional echocardiography, cardiac catheterization, and myocardial biopsy. A coronary arteriogram disclosed normal coronary arteries. She had received diltiazem and meliletine for 9 years. Her functional class, by the New York Heart Association classification, had worsened from II to III since 1995. Two-dimensional echocardiography showed a thrombus in the left ventricle in 1996, and warfarin and captopril were prescribed. Follow-up images showed that 1-123 β-methyl-p-iodophenyl-pentadecanoic acid uptake preceded that of TI-201.

Multiple-gated radionuclide ventriculography (RNV) with 99mTc-labeled human serum albumin was performed on a 63-year-old man suspected of having angina pectoris. RNV was obtained in the left anterior oblique position at rest and during exercise. During mild exercise, the patient had chest pain, and an ECG showed ST-segment elevation in leads II, III, aVF, and V1 through V5. After we acquired …

Exercise stress perfusion imaging was performed in a 55-year-old man suspected of having angina pectoris. During mild exercise, he had chest pain, and an ECG showed ST-segment elevation in leads aVL and V1 through V4. Then, 370 MBq of 99mTc-tetrofosmin was injected intravenously, and 1 minute after injection, 0.3 mg of nitroglycerin was administered sublingually twice. 201Tl 111 MBq was injected intravenously immediately after disappearance of …

A 65 year old man presented with chest discomfort accompanied by ST elevation in leads V1–V5 on an ECG. Coronary angiography revealed severe stenosis in the mid portion …

The effects of d1-2-(3'-t-butylamino-2'-hydroxypropylthio)-4-(5'-carbamoyl-2'-thi enyl) thiazole hydrochloride (S-596) were evaluated in 9 normal volunteers. Exercise echocardiography was performed in the semi-supine position before and 2, 4 and 24 hours after the oral administration of 15 mg of S-596. Two hours after administration, resting heart rate was unchanged, compared with control, but systolic blood pressure at rest was slightly decreased (114 +/- 6 vs 106 +/- 10 mmHg, p less than 0.05). Left ventricular dimensions were unchanged, but shortening fraction was increased in the resting state (30.3 +/- 4.6 vs 33.1 +/- 4.8%, p less than 0.05). During exercise on oral S-596, heart rate and systolic blood pressure responses were reduced (127 +/- 11 in control vs 108 +/- 6 beats/min on S-596, 198 +/- 25 vs 168 +/- 23 mmHg, p less than 0.001 and 0.05, respectively). Left ventricular end-diastolic dimension was not significantly altered by S-596 compared with the preceding control exercise test; however, end-systolic dimension was significantly larger after beta blockade with S-596 (2.6 +/- 0.4 vs 3.0 +/- 0.4 cm, p less than 0.05). Shortening fraction and cardiac output decreased significantly (43.7 +/- 3.7 vs 40.0 +/- 5.7%, 9.5 +/- 1.4 vs 8.4 +/- 1.3 L/min, p less than 0.05 and 0.01, respectively). These effects of S-596 were maximal at 2 hours after oral administration with reduced response of heart rate to exercise lasting for 24 hours. Compared with the effects of propranolol (30 mg, given orally) in the same subjects, beta-adrenergic blockade during exercise with S-596 was equivalent to or greater than that of propranolol. Thus, S-596 has little, if any, effect on resting left ventricular performance, but demonstrates potent negative chronotropic and inotropic effects during exercise in normal human subjects. Its beta-adrenergic blocking action also has long acting properties, especially its chronotropic effect.

We performed dual M-mode exercise echocardiography, which records left ventricular (LV) and left atrial (LA) echocardiograms simultaneously, in 10 normal subjects to investigate mechanisms of cardiac adaptation to dynamic exercise. The LV end-diastolic dimension (EDD) increased significantly as exercise increased from mild to moderate (3-5%, p less than 0.05 and 0.001). At peak exercise the EDD was slightly increased, but it returned to the baseline during recovery. The LV end-systolic dimension (ESD) showed a progressive decrease with the severity of exercise (5-13%, p less than 0.05 and 0.001). It decreased further immediately after exercise (17-20%) and then returned to the resting value. The LV stroke dimension and fractional shortening increased as exercise changed from mild to moderate and reached a plateau at peak exercise. During recovery, they showed a transient increase and then decreased. By contrast, the LA dimensions, both maximum and minimum, increased significantly as exercise changed from mild to moderate (15-16% and 16-19%, p less than 0.01 and 0.001, respectively), but they were lower at peak exercise (12 and 14%). They returned rapidly to the resting values immediately after exercise. Thus, during exercise, LV function is augmented by the Frank-Starling mechanism in combination with increased contractility, while the LA is enlarged to receive the increased venous return accompanying dynamic exercise. These exercise-induced changes in LV performance return gradually to the resting state, but LA size recovers rapidly after the cessation of exercise.

To investigate left ventricular size and performance during graded submaximal exercise, 14 normal subjects with a mean age of 21 years exercised in a supine position to achieve the target heart rate. Using two-dimensional echocardiography, we recorded and analysed the left ventricular (LV) cross-sectional area and internal dimension at the level of the tips of the mitral valve at rest and during mild, moderate and severe exercise. The heart rate and systolic blood pressure increased substantially from rest to peak exercise (71 +/- 11 to 162 +/- 10 beats/min, 122 +/- 10 to 204 +/- 22 mmHg). The end-diastolic cross-sectional area and internal dimension (EDA & EDD) increased by 1.1-2.2 cm2 (7-13%) and 0.2-0.3 cm (4-7%), respectively, from mild to moderate exercise, (p less than 0.05-0.001). At peak exercise, however, these decreased and showed no statistically significant difference from the values at rest. The end-systolic cross-sectional area and internal dimension (ESA & ESD) decreased by 1.1 to 1.6 cm2 (14-20%) and 0.2-0.3 cm (7-10%), respectively, from moderate to severe exercise (p less than 0.01-0.001). However, the end-systolic values during mild exercise were not significantly different from those at rest. The stroke area (EDA-ESA) and dimension (EDD-ESD) increased by 1.6-2.6 cm2 (19-31%) and 0.2-0.6 cm (25-38%), respectively, during all levels of graded exercise (p less than 0.05-0.001). The percent change of LV cross-sectional area and internal dimension during systole increased gradually from rest to moderate exercise (51.0 +/- 7.1 to 61.9 +/- 4.4%, 35.4 +/- 3.9 to 45.0 +/- 3.7%), respectively, and showed no further increase during peak exercise. The mean circumferential fiber shortening velocity increased sharply from rest to peak exercise (1.27 +/- 0.14 to 2.25 +/- 0.21 circ/sec). These results suggest that the Frank-Starling mechanism operates during mild to moderate exercise, and contractility increases markedly at moderate to severe exercise levels as cardiac performance is augmented during graded submaximal exercise.

Arrhythmogenic right ventricular dysplasia (ARVD) is characterized by right ventricular (RV) myopathic changes and ventricular tachycardia (VT). Myocardial scintigrams obtained by intracoronary injection of TI-201 chloride were useful in the diagnosis of the location and extent of dysplasia in a 23-year-old man.

Masquerading bundle branch block is a rare and unique finding on a 12-lead electrocardiogram, consisting of the pattern of right bundle branch block in the precordial leads and left bundle branch block in the limb leads. We experienced a 77-year-old woman with masquerading bundle branch block. She had been well, but died suddenly 9 months after the diagnosis of masquerading bundle branch block. The presence of masquerading bundle branch block indicates severe degeneration of the conduction system, leading to a poor outcome.

Taking advantage of the fact that the distribution of Thallium-201 in an organ almost parallels the blood flow to the organ, we devised a non-invasive method of simultaneously determining blood flow and its distribution in human organs. With this method, we investigated the effect of exogenous prostaglandin E1 (PGE1) on the central and peripheral circulation. Scintigraphy was performed after two injections of 201Tl chloride, one at rest and one after the administration of PGE1 or saline. In eight subjects given PGE1 (0.2 microgram X kg-1 X min-1, iv), blood pressure fell, whereas both heart rate and cardiac output rose. The fractional distribution was increased in the heart (+13.3 +/- 2.98%, mean +/- SD), but decreased in the liver (-10.2 +/- 1.95%) and gastro-intestinal tract (-7.09 +/- 2.65%). No significant change was observed in the kidneys or leg. The blood flow in all these organs was increased. In the six control subjects given saline, there was no change in these central and peripheral haemodynamics. Thus, the intravenous infusion of PGE1 in man causes uneven blood flow distribution in heart, liver, kidney, gastro-intestinal organs and leg muscles, despite increased blood flow to all these organs. The method used in this study is relatively non-invasive and useful in evaluating organ blood flow in man, and seems to be widely applicable to physiological and pharmacologic research.

Motion is a powerful source of three-dimensional (3D) information about visual objects. For example, we can easily identify the structure of rotating objects solely on the basis of motion signals. This phenomenon is called Structure-From-Motion (SFM) perception. But the neural mechanisms underlying SFM have not been fully clarified. In the present study, I studied if the dorsal division of the medial superior temporal area (MSTd) in the macaque, which contains many neurons sensitive to complex motion stimuli, has activity related to SFM processing. As the simplest form of 3D structure, I chose a planar stimulus, and examined the relation between the neural responses and the simulated 3D-orientation of the plane defined by motion cues.I recorded from 114 MSTd neurons while monkeys were performing a visual fixation task. These neurons responded to a basic set of optic flow patterns such as translation, expansion/contraction, and rotation. I examined responses of these neurons to rotating plane stimuli that were composed of random dots and that simulated rotating planes with various 3D-orientations. The simulated 3D-orientation can be characterized by two parameters, namely, tilt and slant, and I examined whether the MSTd neurons exhibited selectivity to these two parameters.I found that most MSTd neurons tested (97 out of 114) responded to the plane stimuli, and many neurons (65 out of 97) exhibited selectivity to tilt and/or slant. Of 97 neurons, 18% (17/97) were selective only to tilt, 24% (23/97) only to slant, and 26% (25/97) to both. Certain stimulus components such as local translation, local speed, local speed gradients and distribution of velocities vary together with the change in the tilt and/or slant. However, control experiments have rejected the possibility that selectivity is explained solely by the sensitivity to such components.These results suggest that MSTd neurons are sensitive to stimulus features specific to the simulated 3D-orientation of the rotating plane stimuli and suggest that area MSTd is involved in SFM processing.