Exercise-induced intra-ventricular gradients as a frequent potential cause of myocardial ischemia in cardiac syndrome X patients

<p>Abstract</p> <p>Background</p> <p>The development of intra-ventricular gradients (IVG) during dobutamine or exercise stress is not infrequent, and can be associated to symptoms during stress.</p> <p>The purpose of this study was to assess the occurrence of IVG during exercise stress echocardiography in cardiac syndrome X patients.</p> <p>Methods</p> <p>We prospectively evaluated 91 patients (pts) mean aged 51 ± 12 years (age ranged 20 to 75 years old), 44 of whom were women. All pts had angina, positive exercise ECG treadmill testing, normal rest echocardiogram and no coronary artery disease on coronary angiogram (cardiac X syndrome). After complete Doppler echocardiographic evaluation with determination of left ventricular outflow tract index (LVOTi), relative left ventricular wall thickness (RLVWT) and left ventricular end-diastolic volume index (LVDVi), all patients underwent stress echocardiography with two-dimensional and Doppler echographic evaluation during and after treadmill exercise.</p> <p>Results</p> <p>For analysis purpose patients were divided in 2 groups, according to the development of IVG. Doppler evidence of IVG was found in 33 (36%) of the patients (Group A), with mean age 47 ± 14 years old (age ranged 20 to 72 years) and with a mean end-systolic peak gradient of 86 ± 34 mmHg (ranging from 30 to 165 mmHg). The IVG development was accompanied by SAM of the mitral valve in 23 pts. Three of these pts experienced symptomatic hypotension. Ten were women (30% pts). 58 pts in group B, 34 of whom were women (59%) (p = 0,01 vs group A), mean aged 53,5 ± 10,9 years old (age ranged 34 to 75 years) (p = 0,03 vs group A), did not develop IVG. LVOTi was 10,29 ± 0,9 mm/m²in group A and 11,4 ± 1 mm/m²in group B (p < 0,000); RLVWT was 0,36 ± 0,068 in group A and 0,33 ± 0,046 in group B (p < 0,01); LVDVi was 44,8 ± 10 ml/m²in group A and 56 ± 11,6 ml/m²in group B (p = 0,000).</p> <p>Conclusion</p> <p>1. A significant number of patients with cardiac X syndrome developed IVG during upright exercise in treadmill. These pts (group A) are mainly males and younger than those who did not develop IVG.</p> <p>2. The development of IVG and mitral valve SAM on exertion seems to be associated with ST segment downsloping during stress testing in patients without epicardial coronary disease.</p> <p>3. The development of IVG and mitral valve SAM seems to be associated with lower LVOTi, lower LVDVi and higher RLVWT.</p

Urinary kallikrein excretion and blood pressure response to angiotensin converting enzyme inhibitors and calcium antagonists in hypertensive patients

OBJECTIVE: To investigate whether the hypotensive effects of angiotensin converting enzyme (ACE) inhibitors in comparison with those of calcium antagonist might be predicted by urinary kallikrein activity, a marker of the activity of the renal kallikrein-kinin system. DESIGN: Seventy-five essential hypertensive patients were randomly assigned to treatment with ACE inhibitors (enalapril or lisinopril 20 mg once a day) or with calcium antagonists (nifedipine 20 mg twice a day or lacidipine 4 mg once a day). Fifty-four had normal (NK) and 21 low (LK) kallikrein activity. Blood pressure was measured after 2 weeks, and 3 and 6 months. Patients whose diagnostic blood pressure, 2 weeks after the first dose, decreased by at least 15 mmHg or was < or = 90 mmHg were defined as responders. The others were defined as non-responders. In non-responders a second drug was added and the patients were not considered for further analysis. METHODS: Urinary kallikrein activity was determined by a spectrophotometric assay using a synthetic chromogenic substrate. RESULTS: After 2 weeks therapy with ACE inhibitors 88% of NK patients were responders, whereas in the LK subgroup 40% were responders, a significant difference between subgroups. For the patients treated with calcium antagonists, conversely, 59% of NK patients were responders in comparison with 82% of the LK subgroup, a significant difference between drug groups. After 3 and 6 months of treatment blood pressure was significantly lower in NK patients treated with ACE inhibitors and in LK patients treated with calcium antagonists. In the NK group on ACE inhibitors the mean arterial pressure after the first dose was significantly related to that observed after 6 months (n = 0.71, P < 0.01). CONCLUSIONS: Our data indicate that urinary kallikrein activity may represent an index to predict the chronic antihypertensive effect not only of ACE inhibition but also of calcium antagonism, and support the concept that the renal kallikrein-kinin system might play some contributory role in modulating the hypotensive action of ACE inhibitor