and Ken-ichi KOBAYASHI Central muscarinic receptors play an important role in the regulation of cardiac vagal nerve activity. We studied the inhibition of central muscarinic receptors and sympathetic nerve function in humans, since very little information is currently available on this subject. We examined the effects of graded doses of atropine (five doses, range 0.001 to 0.016 mg/kg) on heart rate, arterial pressure, heart rate variability, and muscle sympathetic nerve activity in 13 healthy young volunteers. Atropine caused biphasic effects on heart rate and the high-frequency (HF) power of R-R interval variability. At lower doses (0.002 mg/kg for heart rate, 0.001 mg/kg for HF power), atropine decreased heart rate and increased HF power. In contrast, at higher doses, atropine increased heart rate and decreased HF power. Low-dose atropine significantly attenuated muscle sympathetic nerve activity, burst rate (bursts/min) by -30.5±6.0% and burst incidence (bursts/100 heart beats) by -23.8 ± 6.9% at 0.002 mg/kg. Systolic and diastolic arterial pressure did not change with atropine infusion. Low-dose atropine (0.002 mg/kg) did not significantly affect either low frequency (LF) power or LF/HF. These results suggest that central muscarinic receptors may modulate not only cardiac vagal nerve activity but also sympathetic nerve activity in the skeletal muscle vasculature.
The outcome of patients with pulmonary hypertension (PHT) and antiphospholipid syndrome (APS) is usually fatal. The authors report the rare case of a patient with primary APS and nonthrombotic PHT who has survived for twenty years after the onset of PHT. In this case, the patient's PHT resembled the primary idiopathic variety with clear lung fields and normal perfusion on the lung scan, and the combination therapy with nitrate, digoxin, and diuretics had been performed. During her clinical course over twenty years, she had not experienced any critical pulmonary thrombosis that influenced the progression of nonthrombotic PHT or any other severe systemic involvement of APS.
A 30-year-old man was admitted to our hospital for left lobar pneumonia with septic shock. Acute left-sided heart failure became evident as sepsis developed. Echocardiography revealed diffuse severe hypokinesis of the left ventricle (LV) and a pulmonary artery catheter showed Forrester subset II hemodynamics. Along with amelioration of sepsis and decrease of the serumconcentrations of tumor necrosis factor-a and interleukin-6, LV hypokinesis improved. It is suggested that the patient's heart failure mayhave been due to functional depression of myocardial contractility resulting from a direct effect of the cytokines towards the cardiomyocytes, the socalled "septic myocardial depression". (Internal Medicine 42: 60-65, 2003)
coronary artery fistula is an uncommon congenital malformation of the heart. The majority of these anomalies involve only 1 coronary artery, and only rarely are 2 coronary arteries involved. [1][2][3][4][5] It has been reported that approximately 5% of all coronary artery fistulas occur bilaterally. 1 Bilateral coronary artery fistulas usually communicate with a single site in a cardiac chamber or vascular structures, and fistulas with multiple sites of drainage are extremely rare. This report describes a very rare case of bilateral coronary artery fistulas draining into the main pulmonary artery, the great cardiac vein and the right atrium. Case ReportA 49-year-old woman was referred to hospital for evaluation of a cardiac murmur. On admission, her blood pressure was 148/82 mmHg. The pulse rate was 68 beats/min and regular. A high-pitched continuous murmur of grade 3/6 was heard best in the third intercostal space at the left sternal border. The laboratory data were all normal. The electrocardiogram was normal as was the chest X-ray. No significant ST-T wave changes were found at a maximal heart rate of 181 beats/min during treadmill exercise testing. Stress thallium-201 myocardial scintigraphy showed no perfusion defects.At cardiac catheterization, the pressures, cardiac output and left ventricular function were all normal. Selective coronary arteriography revealed no fixed narrowing of any coronary artery, but showed 4 coronary artery fistulas. One fistula originated from the proximal part of the left coronary anterior descending coronary artery and connected to the main pulmonary artery (Fig 1). Three coronary artery Japanese Circulation Journal Vol.62, October 1998 fistulas arising from a conal branch of the right coronary artery also were noted (Fig 2). These fistulas drained into the main pulmonary artery, the right atrium and the great cardiac vein. The calculated pulmonary-to-systemic flow ratio (Qp/Qs) was 1.3:1.0. She received no medication and advice for endocarditis prophylaxis was given. DiscussionThe actual incidence of bilateral coronary fistulas is not known. Levin et al reviewed 363 cases of coronary fistulas and noted that such fistulas were single in the majority of cases, and only 19 cases (5%) were multiple, originating from both coronary arteries. 1 The coronary artery fistulas drained into the right ventricle in 41%, the right atrium in 26%, and the pulmonary artery in 17% of their cases. Coronary artery fistulas to the cardiac chambers arise dueJpn Circ J 1998; 62: 783 -784 (Received May 13, 1998; revised manuscript received July 1, 1998; accepted July 10, 1998) A 49-year-old woman presented with bilateral coronary fistulas with multiple sites of drainage. She had been referred to hospital for evaluation of a cardiac murmur, and a coronary arteriogram revealed multiple coronary fistulas. One fistula originated from the proximal part of the left anterior descending coronary artery and connected to the main pulmonary artery. Three coronary artery fistulas arised from a conal branc...
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