Evaluation of myocardial bridges with 64-slice computed tomography coronary angiography.

OBJECTIVE: The aim of this study is to report the characteristics of myocardial bridging (MB) using 64-slice computed tomography and to demonstrate the association between atherosclerotic coronary artery disease (CAD) and MB. METHODS AND RESULTS: In 990 consecutive patients who underwent multi-slice computed tomography (MSCT) coronary angiography for suspected or known coronary artery disease, myocardial bridge evaluation was performed with axial, curved multiplanar reconstruction and three-dimensional volume-rendered images. 265 bridged segments were identified in 223 (22.5%) patients. Multiple MBs on left coronary arteries were found in 41 patients. Most of the MBs were in the LAD (62.6%), followed by the obtuse marginal artery (14.7%) and diagonal artery (14.3%). The average length of MBs was 14 +/- 7 mm, and the average depth was 1.6 +/- 11 mm. No significant difference was observed between patients with and without MB on the middle LAD in respect of age, gender, prevalence of diabetes, hyperlipidaemia, hypertension, current smoking and prevalence of atherosclerotic plaques at the proximal LAD. On the other hand, prevalence of atherosclerotic plaques at the distal LAD were significantly lower in patients with MB on the middle LAD (3.5% vs. 19.7%, P: 0.0001). CONCLUSIONS: The presence and morphological characteristics of MB and its relation with atherosclerotic plaques in the involved coronary artery can be comprehensively analysed with 64-slice computed tomography coronary angiography. Atherosclerosis is a common finding in segments proximal to MB, but the prevalence of plaques in equivalent segments (proximal LAD in our study) is not higher than in patients under similar coronary artery disease risk and without MB. On the other hand, prevalence of atherosclerotic plaques at the distal LAD was significantly lower in our patients with MB on the middle LAD. Finally, we suggest that rather than causing proximal atherosclerosis, MB might have a more important role in the protection of distal segments of the bridged arteries from atherosclerosis.

Safety and efficacy of patient preparation with intravenous esmolol before 64-slice computed tomography coronary angiography.

OBJECTIVE: To evaluate the safety and efficacy of heart rate reduction by intravenous esmolol in patients who are assigned for coronary angiography with 64-slice computed tomography (CT). METHODS: Five hundred consecutive patients were prospectively analyzed. Patients with an initial heart rate less than 65 beats per minute (bpm) did not receive esmolol. Patients with a heart rate between 65 and 80 bpm received a bolus dose of 1 mg/kg intravenous esmolol. Patients with an initial heart rate between 80 and 90 bpm received a bolus dose of 2 mg/kg intravenous esmolol. An additional 1 mg/kg intravenous esmolol was given to the patients when the target heart rate was not reached with the first bolus dose. Patients with an initial heart rate more than 90 bpm received 50 mg atenolol PO, and were reevaluated after 1 h. RESULTS: A total of 391 patients with a heart rate > or =65 bpm before multislice computed tomography (MSCT) examination received intravenous esmolol with a mean dose of 158+/-55 mg. Initial and final mean heart rates were 80+/-11 bpm and 63+/-7 bpm, respectively (P<0.0001). Heart rate below 65 bpm was reached in 265 (65%) of these 391 patients. Only four patients (1%) had a final heart rate above 80 bpm before MSCT imaging. Four of the 391 patients (1%) had a final heart rate below 50 bpm. CONCLUSION: Intravenous esmolol is safe and effective to reach the optimum heart rate in patients assigned for MSCT.

Diagnostic performance of 64-slice computed tomography coronary angiography to detect significant coronary artery stenosis.

OBJECTIVE: We aimed to determine the diagnostic accuracy of 64-slice multi-slice computed tomography (MSCT) to detect significant coronary artery stenosis with comparison to conventional coronary angiography (CCA). METHODS: In 100 patients (70 men, average age 58 +/- 10 years and age range 31-75 years) scheduled to have conventional coronary angiography, MSCT was performed before catheterization (within 2 months). All patients were in sinus rhythm, able to hold breath for 15 seconds, and had serum creatinine levels < 1.5 mg/dl. MSCT scans were analysed by a radiologist and a cardiologist. Sensitivity, specificity, positive and negative predictive values for the detection of significant stenoses by MSCT in comparison with CCA were calculated on patient, vessel, and segmental bases. RESULTS: 64-slice computed tomography is able to detect significant coronary artery stenosis on a segmental basis with a sensitivity of 88% and specificity of 99% when compared with CCA. All patients with significantly stenotic coronary artery disease are correctly diagnosed. The presence of significant stenosis was correctly diagnosed by MSCT in 126 of 144 segments. Twelve non-significant lesions on CCA were overestimated by MSCT. On vessel-based analysis, the sensitivity and specificity of MSCT for detecting significant stenosis were 91% and 97%, respectively. CONCLUSION: Our results indicate that 64-slice computed coronary angiography is a reliable diagnostic modality for the detection of significant coronary artery stenosis in patients with sinus rhythm and scheduled to have CCA, but still has limitations of diagnostic performance on a per-segment and per-vessel basis.

B-type natriuretic peptide levels in patients with COPD and normal right ventricular function.

INTRODUCTION: Evidence suggests that elevated plasma levels of B-type natriuretic peptide (BNP) are found in patients with chronic obstructive pulmonary disease (COPD) and right ventricular dysfunction. We examined the effects of exercise on plasma BNP levels in patients with COPD who have normal right ventricular function METHODS: Seventeen patients with a diagnosis of COPD and normal right ventricular function demonstrated by radionuclide ventriculography, and 17 age-and sex-matched healthy subjects underwent a treadmill exercise test. Plasma BNP levels were measured sequentially before, immediately after, and 1 hour after the exercise test RESULTS: The mean plasma BNP+/-standard deviation levels of the COPD and control groups before exercise were 21.3+/-16 pg/ml and 13.4+/-11 pg/ml, respectively (P>0.05). Mean plasma BNP level measured immediately after exercise was 37.9+/-31 pg/ml in the COPD group, reflecting a statistically significant increase when compared with the initial value (P<0.05). The control group did not show any significant change in plasma BNP levels after the exercise test CONCLUSIONS: Exercise induces an increase in plasma BNP levels in patients with COPD who do not have right ventricular dysfunction at rest. Measurement of exercise-induced BNP levels may be a useful alternative to pulmonary artery catheterisation in identifying the patients who are likely to benefit from long-term oxygen therapy.

Prevalence of coronary artery disease in low to moderate-risk asymptomatic women: a multislice computed tomography study.

OBJECTIVES: Traditional risk factors may underestimate the burden of subclinical atherosclerosis in women. Recently, multislice computed tomography (MSCT) has become widely available in detecting early coronary artery disease (CAD). We sought the prevalence of CAD in low to moderate-risk asymptomatic women by MSCT coronary artery calcium (CAC) scoring and coronary angiography. STUDY DESIGN: The study included 185 women (mean age 57+/-12 years) without known CAD and diabetes, with low or moderate risk for CAD based on traditional risk scoring. Coronary artery calcium scoring and coronary angiography were performed by MSCT, which included a segment-based plaque detection and characterization of calcification. The plaques were classified based on the luminal stenotic effect (>50%). Patients with = or >1 stenotic plaque were classified as having obstructive CAD. Angiographic findings were compared with calcium scores. RESULTS: Coronary artery calcium scoring and coronary angiography detected CAD in 63 (34.1%) and 100 (54.1%) women, respectively. In both groups, women were significantly older and had higher prevalences of hypertension and dyslipidemia. Coronary angiography showed CAD in 41 women (41%; 14.6% were obstructive) without CAC. These women were significantly younger than those with a positive CAC score (p<0.01). Age (p<0.02) and hypertension (p<0.05) were found as independent predictors of CAD detected by coronary angiography. CONCLUSION: Multislice computed tomography identified a subset of low-risk women who might be at higher risk than that suggested by current risk stratification strategies. Women, especially having hypertension and dyslipidemia may be potential candidates for further risk stratification by MSCT coronary angiography.

Interaction between C-reactive protein and endothelin-1 in coronary artery disease.

BACKGROUND: Increased concentrations of serum C-reactive protein (CRP) have been reported to predict major cardiovascular events in patients with coronary artery disease (CAD). Increased concentrations of endothelin-1 (ET-1) are also associated with poor prognosis after myocardial infarction. HYPOTHESIS: We tested the hypothesis that ET-1 might contribute to CRP in prediction of adverse outcome in CAD. METHODS: Serum high sensitive CRP and plasma ET-1 levels of 40 patients who have stable CAD and 25 control subjects were measured, and correlation analysis between these molecules was performed. RESULTS: Mean high sensitive CRP was 8.64 +/- 12.73 mg/l, and mean ET-1 was 8.24 +/- 7.06 pg/ml in the CAD group. We found that there was no statistically significant correlation between high sensitive CRP and ET-1 in either CAD group (p = 0.82), or the control group (p = 0.85). In a subgroup of 13 patients who were not under statin treatment, we found a strong correlation between the levels of these molecules (p = 0.01). CONCLUSION: Our study does not clearly support or exclude a link between CRP and ET-1 in patients who have stable CAD.

Retrograde balloon dilatation of right coronary artery lesions through a venous graft.

Percutaneous coronary intervention (PCI) using retrograde approach through venous grafts or collateral vessels is a promising option for chronic total occlusion (CTO) lesions in which antegrade crossing is not possible. We describe a successful retrograde balloon dilatation of right coronary artery lesions through a venous graft in a patient with a previous coronary bypass surgery.

Paclitaxel-induced ST-segment elevations.

A 51-year-old woman presented with severe chest pain minutes after starting intravenous paclitaxel as a part of the systemic chemotherapy due to ovarian carcinoma. The electrocardiogram (ECG) revealed sinus rhythm with ST-segment elevations in inferior and anterior leads. The ST-segment elevations resolved immediately after sublingual nitroglycerine. Cardiac troponin T and CPK MB levels remained in the normal range at repeat measurements. It was presumed that in spite of standard premedication, paclitaxel had induced acute coronary syndrome with ST-segment elevations in this patient.

Giant hydatid cyst of the interventricular septum mimicking acute myocardial infarction on ECG: an unusual cause of ST segment elevation.

Hydatid disease is a parasitic infection caused by larvae of Echinococcus granulosus, which is still endemic in many cattle-raising areas. Cardiac involvement is a rare, but potentially a very serious complication of the hydatid disease. The diagnosis of cardiac cyst hydatid may be difficult due to the nonspecific symptoms and varying clinical presentations. With this report, we describe a case of giant hydatic cyst of the interventricular septum that caused ischemic changes on ECG, mimicking acute myocardial infarction. The final diagnosis was made by combining echocardiography, MRI, and serological tests. Surgical resection of the cyst, followed by albendezol treatment yielded a favorable outcome.

Acute myocardial infarction in a 24 year-old man possibly associated with sibutramine use.

Sibutramine is an anti-obesity drug, which acts by inhibiting neuronal re-uptake of noradrenaline and serotonin. Although the most frequently seen effect of sibutramine on cardiovascular system is an increase in blood pressure and pulse rate, rare but severe side effects such as sibutramine-induced ventricular arrhythmias, heart failure and cardiovascular disease-related death are also reported. We describe a 24 year-old man with low atherosclerotic risk profile who had acute myocardial infarction possibly associated with sibutramine use.

Prevalence of left main coronary artery disease among patients referred to multislice computed tomography coronary examinations.

We have evaluated the prevalence of left main coronary artery disease (LMCAD) among patients referred to multislice computed tomography (MSCT) coronary angiography examinations. The study Group comprised of 1,000 consecutive patients (750 male and 250 female; mean age 53+/-12 years) who underwent successful 64-slice MSCT examinations. Left main coronary artery (LMCA) was classified into three Groups: normal LMCA; nonsignificant LMCAD with coronary plaques resulting in obstructions 50%. We have found that 24 patients (2.4%) had significant LMCAD. Additional 200 patients (20%) had nonsignificant LMCAD. Univariate analysis revealed that LMCAD was associated with age, male gender, diabetes, hypertension, hyperlipidemia, typical symptoms, history of previous myocardial infarction and previous percutaneous coronary intervention. Only age and male gender were found as independent predictors for LMCAD in multivariate analysis (P < 0.001 and P = 0.001, respectively,). Angiographic follow-up was avaliable for the 24 patients with significant LMCAD, and conventional coronary angiography confirmed the presence of significant LMCAD in all of these patients. Significant LMCAD was found in 2.4% of the 1,000 patients referred to 64-slice MSCT examinations. Age and male gender were the independent predictors for LMCAD.

Right coronary artery fistula with significant left-to-right shunt.

We present an image of giant fistula between severely enlarged right coronary artery and coronary sinus, which was evaluated by echocardiography, conventional coronary angiography and multislice computed tomography coronary angiography.

Peripartum cardiomyopathy presenting with repetitive monomorphic ventricular tachycardia.

A 30-year-old asymptomatic pregnant woman at 38 weeks' gestation was noticed to have repetitive monomorphic ventricular tachycardia. A dilated left ventricle with moderately reduced systolic function was found on echocardiographic examination. To the best of our knowledge, a case of peripartum cardiomyopathy presenting with repetitive monomorphic ventricular tachycardia has not been previously reported.