Tai Sekine

Right atrium contractility and right ventricular diastolic function assessed by pulsed Tissue Doppler Imaging can predict brain natriuretic peptide in adults with acquired pulmonary hypertension

PURPOSE We evaluated right atrial (RA) contractility and right ventricular (RV) diastolic function in adult patients with acquired chronic pulmonary hypertension (PH) by pulsed Tissue Doppler Imaging (TDI) and assessed their relationship with serum brain natriuretic peptide (BNP). MATERIALS AND METHODS Systolic myocardial wave (Sa), early diastolic myocardial wave (Ea), and late diastolic myocardial wave (Aa) at the tricuspid annulus were recorded in 77 consecutive patients with acquired PH. Early (E) RV inflow waves were recorded from 4-chamber views. RV Aa was regarded as the parameter of RA contractility and RV E/Ea was taken as the parameter of RV diastolic function using TDI. RESULTS All subjects had elevated BNP (mean 188.9 +/- 244.0 pg/dl) and pulmonary arterial systolic pressure (PASP) estimated at 62.9 +/- 26.7 mm Hg. BNP levels were positively correlated with RV E/Ea, Aa and PASP (r = 0.47, p < 0.0001 and r = 0.35, p < 0.01, respectively) but negatively with Aa (r = -0.29, p < 0.05). Next, all predictor variables were used in a multiple regression model with serum BNP values as dependent variables, refined to include 3 predictors: RV E/Ea, Aa, and PASP, which were all found to influence serum BNP values (p < 0.0001) by the formula Y = 34.1X1**-19.11X2**+2.95X3* (**p < 0.001, *p < 0.01) where Y = BNP, X1 = E/Ea of RV, X2 = Aa, and X3 = PASP (standard regression coefficients were 0.37, -0.34 and 0.34, respectively). CONCLUSION Serum BNP correlates with RA contractility and RV diastolic dysfunction by RV TDI in adults with acquired PH. Increased BNP may be related to decreased RA systolic function and RV diastolic function in these patients.

The impact of sleep deprivation on the coronary circulation

Epidemiologic studies have reported that sleep deprivation is associated with cardiovascular events. However, it remains unknown how sleep deprivation affects the coronary circulation. We assessed the impact of sleep deprivation on the coronary circulation using coronary flow velocity reserve (CFVR) measurements with transthoracic Doppler echocardiography. We studied 26 healthy male volunteers. Each subjects CFVR was measured in the morning after sleep deprivation (less than 4 h) or normal sleep (more than 7 h) on different days. Sleep durations were 3.7 ± 0.9 h (sleep deprivation) and 7.1 ± 0.2 h (normal sleep). CFVR after sleep deprivation was significantly lower than that after normal sleep (3.3 ± 0.6 versus 4.2 ± 0.9, p<0.001). Short sleep duration attenuated CFVR compared with normal sleep duration. This finding suggests that sleep deprivation might serve as a trigger for cardiovascular events.

Serum asymmetric dimethylarginine as a marker of coronary microcirculation in patients with non-insulin dependent diabetes mellitus: correlation with coronary flow reserve

Abnormalities of coronary microcirculation without large vessel atherosclerosis have been known in patients with non-insulin dependent diabetes mellitus (NIDDM). Coronary flow reserve (CFR) has been considered an important physiological parameter in the coronary circulation reflecting the function of large epicardial arteries and the microcirculation, including endothelial function. Reduced CFR and impaired endothelium mediated, nitric oxide dependent coronary vasodilatation1,2 have been observed in NIDDM without overt coronary artery disease. Asymmetric dimethylarginine (ADMA) is a major endogenous nitric oxide synthase inhibitor and has been considered a novel risk factor of cardiovascular disease.3 Serum or plasma concentration of ADMA is increased in patients with NIDDM3 and may attenuate vascular function. However, to our knowledge, the relation between ADMA and CFR has not been examined in patients with NIDDM. Our goal was to examine the relation between serum ADMA concentration and CFR in patients with NIDDM by means of non-invasive transthoracic Doppler echocardiography. We studied 47 patients with NIDDM without a history of cardiovascular disease. We limited our study population to non-smokers and patients treated with diet or oral hypoglycaemic agents alone. All patients underwent two dimensional echocardiography and a treadmill exercise test …

Doppler imaging predicts cardiac events in chronic pulmonary thromboembolism

PURPOSE We evaluated whether right ventricular (RV) diastolic dysfunction assessed by pulsed tissue Doppler imaging (TDI) predicts cardiac events in patients with chronic pulmonary thromboembolism (CPTE). MATERIALS AND METHODS In 63 consecutive patients with CPTE, early diastolic myocardial velocity (Ea) at the tricuspid annulus by TDI and early diastolic tricuspid inflow (E) by conventional pulsed Doppler were obtained, and E/Ea was calculated as an indicator of RV diastolic dysfunction. Brain natriuretic peptide (BNP) and other echo parameters were also obtained. A cardiac event (rehospitalization caused by congestive heart failure or cardiac death) was the study endpoint. Incidence of cardiac events was determined over a 374+/-451 day follow-up period. RESULTS In the follow-up period twelve patients had cardiac events. We divided patients into group A with cardiac events and group B without events. E/Ea was significantly increased in group A as compared with group B (8.3+/-4.1 vs. 5.7+/-2.6, p<0.01). BNP was higher in group A than group B (221+/-191 vs. 121+/-140 mg/dl, p<0.05), and in addition E/Ea was significantly positively correlated with BNP (r=0.48, p<0.001). A logistic regression model for predicting cardiac events was constructed and E/Ea was associated with an increased incidence of cardiac events (relative risk=1.33, 95% CI 1.00-1.75). CONCLUSION Elevated values of E/Ea obtained by TDI may predict cardiac events in patients with CPTE. BNP may also be a significant predictor.

Cibenzoline improves coronary flow velocity reserve in patients with hypertrophic obstructive cardiomyopathy

The effect of cibenzoline, a class-Ia antiarrhythmic drug, on coronary flow velocity reserve (CFVR) was examined in patients with hypertrophic cardiomyopathy using transthoracic Doppler echocardiography. Coronary flow velocity reserve was assessed in 11 patients with hypertrophic obstructive cardiomyopathy (HOCM) and 12 patients with hypertrophic nonobstructive cardiomyopathy (HNCM), before and after the intravenous administration of cibenzoline (1 mg/kg). Coronary hyperemia was induced by an intravenous infusion of adenosine triphosphate and CFVR was calculated as the ratio of hyperemic to basal mean coronary diastolic flow velocity. At baseline, CFVR was significantly correlated with left ventricular outflow tract pressure gradient (LVPG) in patients with HOCM (r = 0.67, P < 0.03). In patients with HOCM, administration of cibenzoline significantly improved impaired CFVR (2.0 ± 0.8 to 3.0 ± 1.0, P < 0.001), and reduced LVPG (55 ± 30 to 23 ± 18 mmHg, P < 0.001), while CFVR remained unchanged in patients with HNCM (2.6 ± 0.9 to 2.9 ± 0.8, P not significant). Cibenzoline not only reduces LVPG but also improves CFVR in patients with HOCM. In addition left ventricular outflow obstruction plays an important role in impaired coronary circulation in patients with HOCM.

Comparison of three techniques for evaluation of de novo asymptomatic pulmonary arterial thrombosis following deep vein thrombosis in total knee arthroplasty

PURPOSE Deep venous thrombosis (DVT) following total knee arthroplasty (TKA) frequently results in pulmonary arterial thrombosis (PAT). Using multislice-CT (MSCT), we evaluated the incidence of de novo asymptomatic PAT following DVT in subjects undergoing TKA and compared these results by ventilation-perfusion (VP) lung scintigram and ultrasonography of the lower extremities. MATERIALS AND METHODS Twenty-five asymptomatic subjects (5 males, 53-82 years old, receiving anticoagulant therapy) underwent enhanced MSCT, VP lung scintigram, and ultrasonography of the lower extremities before and 7 days after TKA. RESULTS Among 25 subjects, 2 were found to have asymptomatic PAT and DVT, respectively, by pre-TKA MSCT. In the remaining 23 subjects, the post-TKA MSCT detected PAT in 7 subjects (30.4%) and DVT in 6 (26.1%). Those 16 subjects without evidence of PAT on the post-TKA MSCT also had no VP mismatches on their VP lung scintigrams. Additionally, all subjects without evidence of DVT on the post-TKA MSCT also showed no evidence of DVT by ultrasonography. Of the 7 subjects in whom PAT was detected by post-TKA MSCT, VP mismatch was shown by lung scintigraphy in 2 and DVT was confirmed by MSCT in both. No patient had VP mismatch without PAT, and 2 subjects with PAT and VP mismatch had DVT. Conversely, DVT was not revealed by ultrasonography among the 6 subjects (26.1%) in whom DVT was detected in the lower extremities by post-TKA MSCT. However, blood flow abnormalities were shown by ultrasonography of the lower extremities in 4 of the 6 subjects (17.4%). CONCLUSION MSCT was the most sensitive of the 3 methods and could simultaneously evaluate PAT and DVT. The apparent discrepancy between these techniques may be due to MSCTs ability to detect thrombi that do not interfere with blood flow.

Patency of the left subclavian artery following implantation of stent graft to rectify a stenosis, as demonstrated by multislice computed tomography

A 67 year old woman with a thrombosed aortic arch aneurysm, presented with numbness in her left arm and a substantial decrease in blood pressure (122/94 mm Hg), which compared unfavourably with the blood pressure of her right arm (156/90 mm Hg). A conventional angiogram revealed a prominent stenosis in the left subclavian artery, …