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Study objectives: Of the hypertrophic obstructive cardiomyopathies, midventricular obstruction (MVO) often has been overlooked. In this study, hemodynamic parameters in patients with MVO were compared with patients with idiopathic hypertrophic subaortic stenosis (IHSS), following which the specific markers for diagnosis of MVO were examined. Patients and design: Twenty healthy control subjects (mean [ SD] age, 54 8 years), 20 patients with MVO (mean age, 54 13 years), and 12 patients with IHSS (mean age, 58 12 years) participated in this study. Hemodynamic parameters associated with carotid pulse tracing (CPT) and echocardiography were examined. Measurement and results: Left ventricular ejection time (LVET) and left ventricular pressure gradient (LVPG) were greater in patients with IHSS than in patients with MVO (p < 0.0001 for both). However, left ventricular dimensions and interventricular septal thickness did not vary between patients with MVO and those with IHSS. As specific markers for the diagnosis of patients with MVO, two specific CPT patterns, the “spike-and-dip pattern” and the “spike-and-half-dome pattern,” were identified, but no specific markers were observed echocardiographically. Among patients with MVO, both LVPG and LVET were greater in patients with the spike-and-half-dome pattern than in patients with the spike-and-dip pattern (113 34 vs 57 17 mm Hg, respectively [p < 0.0001]; 318 19 vs 281 27 ms, respectively [p 0.0033]), but echocardiographic parameters revealed no significant differences between the two types of MVOs. The pattern of continuous-wave Doppler recordings of the left ventricle in patients with the spike-and-halfdome pattern was identical to that of patients with IHSS, but that of patients with the spike-and-dip pattern exhibited concavity from the onset of systole to the point of maximal velocity. Conclusions: Two specific patterns for the diagnosis of patients with MVO were identified by CPT. These patterns may be strongly related to differences in ejection dynamics. (CHEST 2003; 124:1275–1283)

Study objectives We sought to assess the incidence of transient U-wave inversion during vasospasm of the left anterior descending coronary artery (LAD) with ST-segment depression as opposed to that with ST-segment elevation. Design Retrospective study. Setting Cardiology division of acute-care hospitals. Patients We studied 49 patients with vasospastic angina whose vasospasm was induced in the LAD, not in the left circumflex coronary artery, by intracoronary injection of acetylcholine. Measurements and results The ECG traces obtained during acetylcholine-induced vasospasm of the LAD were examined. Based on the direction of ST-segment shift, the patients were categorized into two groups: the ST-segment elevation group (n = 27) and the depression group (n = 22). There were no differences in age, gender, or cardiovascular risk factors between the two groups. The distribution of the spastic site in the LAD was also similar. A total reduction in luminal diameter during a provoked attack was more often observed in the ST-segment elevation group than in the ST-segment depression group (37% vs 9%, p = 0.02). Collateral circulation to the LAD was found in only one patient in each group. There were no differences between the two groups in heart rate, systolic BP, and double product of heart rate and systolic BP during the attack. The incidence of acetylcholine-induced anginal attack with U-wave inversion in the ST-segment depression group was nearly as high as that in the ST-segment elevation group (77% vs 78%, p > 0.99). Conclusions The development of transient U-wave inversion during vasospasm of the LAD induced by intracoronary injection of acetylcholine does not depend on the magnitude of myocardial ischemia as judged by the direction of ST-segment shift.

Of the hypertrophic obstructive cardiomyopathies, midventricular obstruction (MVO) often has been overlooked. In this study, hemodynamic parameters in patients with MVO were compared with patients with idiopathic hypertrophic subaortic stenosis (IHSS), following which the specific markers for diagnosis of MVO were examined.Twenty healthy control subjects (mean [+/- SD] age, 54 +/- 8 years), 20 patients with MVO (mean age, 54 +/- 13 years), and 12 patients with IHSS (mean age, 58 +/- 12 years) participated in this study. Hemodynamic parameters associated with carotid pulse tracing (CPT) and echocardiography were examined.Left ventricular ejection time (LVET) and left ventricular pressure gradient (LVPG) were greater in patients with IHSS than in patients with MVO (p0.0001 for both). However, left ventricular dimensions and interventricular septal thickness did not vary between patients with MVO and those with IHSS. As specific markers for the diagnosis of patients with MVO, two specific CPT patterns, the "spike-and-dip pattern" and the "spike-and-half-dome pattern," were identified, but no specific markers were observed echocardiographically. Among patients with MVO, both LVPG and LVET were greater in patients with the spike-and-half-dome pattern than in patients with the spike-and-dip pattern (113 +/- 34 vs 57 +/- 17 mm Hg, respectively [p0.0001]; 318 +/- 19 vs 281 +/- 27 ms, respectively [p = 0.0033]), but echocardiographic parameters revealed no significant differences between the two types of MVOs. The pattern of continuous-wave Doppler recordings of the left ventricle in patients with the spike-and-half-dome pattern was identical to that of patients with IHSS, but that of patients with the spike-and-dip pattern exhibited concavity from the onset of systole to the point of maximal velocity.Two specific patterns for the diagnosis of patients with MVO were identified by CPT. These patterns may be strongly related to differences in ejection dynamics.

Study objectives: This study assessed whether the antiplatelet agent cilostazol, which has potent cyclic nucleotide phosphodiesterase type-3 inhibitory activity, affects the ventricular escape rate and neurohumoral factors in patients with third-degree atrioventricular block. Design: Prospective, but nonrandomized, study. Setting: Cardiology division of an acute care hospital. Patients: We studied 12 patients with third-degree intra-His or infra-His atrioventricular block who were in functional class II or III of the New York Heart Association classification. None of the patients had experienced Adams-Stokes attacks. Interventions: These patients were given cilostazol orally at a dose of 200 mg daily for at least 1 week. Measurements and results: Before and after treatment with cilostazol, continuous 24-h ECG monitoring and measurement of plasma natriuretic peptide concentrations were performed. Cilostazol significantly increased the mean (± SEM) total 24-h QRS count from 57,300 ± 2,800 to 74,400 ± 3,200 beats (p = 0.001) and significantly decreased the maximum geometric mean R-R interval over a 24-h period from 1,900 ms (95% confidence interval [CI], 1,700 to 2,100 ms) to 1,600 ms (95% CI, 1,400 to 1,900 ms; p = 0.02), although none of the patients showed the abolishment of the atrioventricular conduction abnormalities. The total 24-h count of premature ventricular beats was not different before treatment (15 beats; 95% CI, 5 to 44 beats) and after treatment (12 beats; 95% CI, 5 to 30 beats; p = 0.57). Treatment with cilostazol significantly decreased the concentration of plasma atrial natriuretic peptide from 88 pg/mL (95% CI, 49 to 160 pg/mL) to 51 pg/mL (95% CI, 32 to 80 pg/mL; p = 0.007) and of brain natriuretic peptide from 166 pg/mL (95% CI, 71 to 389 pg/mL) to 77 pg/mL (95% CI, 30 to 178 pg/mL; p = 0.02). Conclusions: Cilostazol significantly increased the ventricular escape rate and significantly decreased the level of circulating natriuretic peptides. Thus, cilostazol could be safely given to selected patients over the short term with third-degree atrioventricular block.