The relationship between left ventricular functional response to isometric exercise and asynergic contraction and diastolic stiffness

Early detection of hypertension in a patient treated with sunitinib by measuring cardio-ankle vascular index

Cardio-ankle vascular index (CAVI) has been established as a marker of arterial stiffness, which is increased in hypertensive patients. CAVI reflects the stiffness of the aorta, femoral artery, and tibial artery. Sunitinib, multi-targeted tyrosine kinase inhibitor with both anti-angiogenic and anti-tumor activities, has been proved effective in patients with gastrointestinal stromal tumors. However, the treatment with sunitinib is often complicated by side effects such as hypertension. We describe an 84-year-old woman with gastrointestinal stromal tumor, who showed changes in arterial stiffness preceding the appearance of hypertension in the early phase after sunitinib initiation. The patient received sunitinib (50 mg given daily) for gastrointestinal stromal tumor. We assessed the influence of sunitinib on arterial stiffness every 7 days by measuring CAVI. The CAVI, which reflects arterial stiffness, was increased from 9.95 at baseline to 11.65 at 7 days after the initiation of sunitinib, whereas the blood pressure remained unchanged (117/72 and 119/76 mmHg). At 14 days after sunitinib initiation, the blood pressure was increased to 159/89 mmHg, indicating the occurrence of hypertension, while the CAVI was 11.90, the similar level detected at 7 days. Subsequently, sunitinib treatment was discontinued, because of the marked decrease in blood platelets. Both blood pressure and CAVI, together with blood platelets, were restored to the baseline values at 12 days after cessation of sunitinib. In conclusion, the increase in the CAVI preceded the appearance of sunitinib-induced hypertension. Arterial stiffness assessed by CAVI may be useful for early detection of sunitinib-induced hypertension.

Left ventricular response to isometric exercise in aortic valve diseases and its value in the optimal timing of aortic valve replacement

In order to evaluate the left ventricular response to isometric exercise in different types of aortic valve disease, isometric exercise tests were performed during cardiac catheterization in 14 patients with pure aortic stenosis, 20 with combined aortic stenosis and regurgitation, and 18 with pure aortic regurgitation. Patients with angina pectoris in whom coronary angiography had not been performed were excluded. Thirty-seven patients were recatheterized 12 months after aortic valve replacement, and the ventricular response to exercise was re-evaluated. Preoperatively, the ejection fraction did not change significantly during exercise in patients with aortic stenosis, tended to decrease in patients with combined valve lesion, and decreased significantly in patients with aortic regurgitation (p less than 0.001). In the three patients whose ejection fraction during preoperative exercise decreased to below 0.40, it remained below 0.50 after successful aortic valve replacement. It appears possible to reveal left ventricular dysfunction in many patients with aortic regurgitation and in some with combined aortic valve disease by means of isometric exercise. The severely depressed ventricular dysfunction during exercise does not appear to correct totally after surgery.

Effect of coronary artery bypass grafting on left ventricular response to isometric exercise

The left ventricular (LV) response to isometric exercise was evaluated in 20 patients who performed handgrip exercise tests before and 3 months after coronary artery bypass grafting. Preoperative LV ejection fraction (EF) decreased during the handgrip test from 0.57 +/- 0.08 to 0.49 +/- 0.09 (p less than 0.001); the ratio between the LV peak systolic pressure (PSP) and end-systolic volume index (ESVI) did not change. In 12 patients with patent grafts, the LVEF after operation did not change (0.54 +/- 0.06 at rest and 0.56 +/- 0.06 during handgrip exercise) and PSP/ESVI ratio increased from 4.5 +/- 1.5 to 5.6 +/- 2.1 mm Hg/ml X m-2 (p less than 0.001) during exercise. In 8 patients with occluded grafts, the LVEF after operation decreased from 0.56 +/- 0.10 to 0.48 +/- 0.06 (p less than 0.02), whereas PSP/ESVI did not change during handgrip exercise. Thus, the LV response to isometric handgrip exercise appears to improve after coronary artery bypass grafting in patients with patent grafts, but not in patients with 1 or more occluded grafts.

Value of isometric exercise testing during cardiac catheterization in mitral stenosis

To examine the value of preoperative isometric exercise testing during cardiac catheterization in patients with mitral stenosis, the isometric handgrip exercise test was performed on 28 patients during preoperative diagnostic catheterization. Eighteen patients who subsequently underwent mitral valve surgery were recatheterized and reevaluated clinically 12 months after operation. Preoperatively, the patients were divided into 2 groups: 16 whose mean mitral valve pressure gradient increased greater than 4 mm Hg during isometric exercise (group A) and 12 whose pressure gradient decreased or increased less than 4 mm Hg (group B). The ejection fraction remained unchanged and the peak systolic pressure/end-systolic volume ratio increased during isometric exercise in group A (p less than 0.001). In group B, the ejection fraction decreased (p less than 0.001) and the peak systolic pressure/end-systolic volume ratio remained unchanged. In the total group, a positive correlation existed between the change in mean mitral valve pressure gradient during isometric exercise and the changes in measures of left ventricular function during exercise. The patients in group A had a significant improvement in both symptoms and in exercise tolerance as determined by symptom-limited bicycle ergometry after surgery. The patients in group B showed minimal or no symptomatic improvement and their exercise tolerance did not improve. The change in mitral valve pressure gradient during isometric exercise appears to reflect the left ventricular response to exercise.