A case of sinus of Valsalva-right ventricle fistula without a typical aneurysm, and a single origin of the coronary arteries.

Few previous reports have described a sinus of Valsalva fistula without an aneurysm in Japanese patients. A single origin of the coronary arteries is a rare coronary anomaly. We describe a 75-year-old woman with a single origin of the coronary arteries and a sinus of Valsalva fistula without a typical aneurysm. Echocardiography showed turbulent flow from the right coronary sinus of Valsalva to the right ventricle throughout the cardiac cycle. Aortography confirmed the presence of a right coronary sinus of Valsalva-right ventricle shunt jet. Echocardiography and aortography demonstrated that there was no deformity of the sinus of Valsalva. Cardiac catheterization revealed that the left-to-right shunt rate was 29% and the Qp/Qs was 1.41. Aortography and coronary angiography did not identify a right coronary artery originating from the right sinus of Valsalva. Coronary angiography revealed that the right coronary artery arose from the proximal part of the left anterior descending artery and did not detect significant organic stenosis of the coronary artery. She was diagnosed as having a sinus of Valsalva to right ventricle fistula without an aneurysm, and a single origin of the coronary arteries.

Assessing muscle vasodilation using near-infrared spectroscopy in cardiac patients.

BACKGROUND: In patients with chronic heart failure, an inadequate increase in muscle blood flow resulting from impaired vasodilation plays a key role in their exercise intolerance. However, no non-invasive methods to assess muscle vasodilation during dynamic exercise were available. We investigated whether the changes in tissue hemoglobin and myoglobin content (total-Hb + Mb) determined by non-invasive measurement using near-infrared spectroscopy (NIRS) reflect vessel conductance of working muscle during exercise. METHODS AND RESULTS: Sixteen patients (10 patients with normal cardiac systolic function, 6 with cardiac dysfunction) performed incremental bicycle exercise testing. Total-Hb + Mb from the right vastus lateralis muscle was monitored using NIRS. Leg blood flow (LBF) in the right femoral vein was measured using a thermodilution technique every 30-60 s. Leg vessel conductance was calculated as LBF/mean arterial pressure at each time of the measurement. In all cases except 1, the levels of total-Hb + Mb showed significant correlation with the leg vessel conductance (r=0.792 to 0.980). Intra-subject reproducibility of the NIRS measurement was also confirmed in 6 patients. CONCLUSIONS: Total-Hb + Mb from NIRS reflected muscle vasodilation during sub-maximal dynamic exercise in patients with and without cardiac dysfunction, indicating that NIRS provides a valuable method to assess the working muscle vasodilation.

Magnesium sulphate infusion suppresses the cardiac release of noradrenaline during a handgrip stress test.

BACKGROUND: Magnesium has several important cardiovascular effects, but its effect on cardiac sympathetic efferent neuron activity has not been clarified. OBJECTIVES: To examine the effect of magnesium sulphate infusion on cardiac sympathetic efferent postganglionic neuronal liberation of noradrenaline. PATIENTS AND METHODS: Twenty-two patients who underwent cardiac catheterization were randomly allocated to the control group or the magnesium group. Plasma noradrenaline and adrenaline concentrations in the aorta and the coronary sinus were measured. Noradrenaline or adrenaline release from the heart was calculated by dividing the difference in noradrenaline or adrenaline concentration between the aorta and the coronary sinus by that of the aorta. After baseline blood sampling, the control patients and the patients in the magnesium group received intravenous infusion of saline or magnesium sulphate (10 mmol). All patients were then subjected to 3 min of handgrip exercise stress test to augment sympathetic efferent neuronal activity, and the blood sampling was repeated. RESULTS: Although blood pressure was increased by the handgrip stress test, there were no differences in heart rate and blood pressure between the two groups, both at baseline and during the handgrip stress test. The plasma noradrenaline and adrenaline concentrations and noradrenaline or adrenaline release from the heart did not differ between the two groups in the baseline condition. However, the handgrip stress increased plasma noradrenaline concentrations and the cardiac noradrenaline release was increased in the control group, whereas the cardiac noradrenaline release was not increased by the handgrip stress in the magnesium group (P<0.02). CONCLUSIONS: These data indicate that magnesium sulphate infusion suppresses the release of catecholamines by the heart, which is an indirect index of sympathetic efferent neuronal activity.