Clinical results of drug eluting stents compared to bare metal stents for patients with ST elevation acute myocardial infarction.

OBJECTIVE: To investigate the clinical outcomes in patients with ST segment elevation acute myocardial infarction (STEMI) treated with drug eluting stents (DES) versus a matched control group of patients with STEMI treated with bare metal stents (BMS). METHODS: This registry included 122 patients with STEMI undergoing primary coronary angioplasty with DES implantation at our institution. The control group consisted of 506 patients implanted with BMS, who were matched for age, infarct location, and diabetic status. The incidences of major adverse cardiac events (MACE) including target vessel/lesion revascularization (TVR/TLR) and stent thrombosis were assessed up to 12 months. RESULTS: Twelve months follow up showed a non-significant trend towards reduced deaths (3.3% versus 7.1%, P=0.1), significantly reduced recurrent MI (0.0% versus 6.1%, P=0.02), TVR (5.7% versus 15.2%, P=0.006) and TLR (2.5% versus 14.0%, P=0.004) events in the DES group as compared to BMS group. The composite incidences of MACE at 12 months follow-up was lower in the DES group (11.5%) as compared to the BMS group (21.3%, P=0.01). CONCLUSION: According to our experiences, the use of DES in STEMI is safe and effective as compared to BMS. DES was effective in reducing the incidence of restenosis outcomes and overall adverse cardiac events up to 12 months.

Systolic rightward displacement of the left anterior descending artery: a novel cineangiographic sign for tricuspid regurgitation.

A new sign for the detection of tricuspid regurgitation (TR) is described. The systolic displacement of the left anterior descending (LAD) artery during coronary angiography in left anterior oblique (LAO) view was quantitatively calculated in 3 groups of 20 patients each with either TR, mitral stenosis, or normal coronary arteriograms. The mean LAD displacement in the TR group was significantly rightward compared to the other groups. Uniform rightward displacement of the lower two-thirds of the LAD had a 90% sensitivity and 90-95% specificity for the presence of TR. Such displacement is probably the angiographic counterpart of the systolic paradoxical septal displacement demonstrated by echocardiography in patients with right ventricular volume overload. There was a positive correlation between the severity of TR and the magnitude of LAD displacement. Attention to the LAD displacement on LAO view may raise suspicion of TR, and indicate its severity.

Effect of dipyridamole on myocardial perfusion and function using technetium-99m MIBI.

Myocardial perfusion imaging with dipyridamole is an accepted method for diagnosing coronary artery disease. However, the simultaneous effect of dipyridamole on perfusion and function in the detection of coronary artery disease has not been studied extensively. The aim of this study was to investigate this effect using technetium-99m methoxy isobutyl isonitrile (Tc-MIBI) imaging. Twenty-eight patients with proven coronary artery disease participated in a 2-day protocol (rest and then 0.56 mg/kg dipyridamole i.v.) using Tc-MIBI for first-pass radionuclide ventriculography followed by SPECT imaging. Fifteen patients (54%) demonstrated a decrease in left ventricular ejection fraction from rest to dipyridamole and/or wall motion abnormality, while 21 patients (75%) showed abnormal perfusion by dipyridamole MIBI SPECT imaging. Concordance between perfusion and function was 65%. Correlation for one-, two- and three-vessel disease (coronary angiography) to perfusion versus function were: 54% vs. 38%, 80% vs. 60% and 80% vs. 80%, respectively. Left ventricular dysfunction using dipyridamole was noted in patients with multivessel disease, and with multi-reversible perfusion filling defects. We conclude that dipyridamole in combination with Tc-MIBI for assessment of perfusion and function serves as a valuable tool to identify patients with multivessel disease and a high amount of myocardium at risk.

An unusual cause of recurrent angina two years after coronary artery bypass grafting: fistula between internal mammary artery graft to pulmonary vasculature.

A 55-year-old man developed recurrent angina pectoris 2 years after coronary artery bypass grafting. Cardiac catheterization demonstrated that the venous grafts were patent, but selective left internal mammary angiogram showed multiple fistulous connections between the internal mammary artery and the pulmonary vasculature of the left upper lobe. After surgical correction of the fistula, the angina resolved. Only three previous cases of acquired internal mammary artery graft fistulas draining to the pulmonary vasculature have been described. The etiology, clinical presentation, and management of an internal mammary artery fistula to the pulmonary vasculature are discussed.

Segmental early relaxation of the left ventricle.

The clinical, electrocardiographic, and angiographic findings of 90 patients, whose RAO 30 degrees left ventriculograms showed segmental early relaxation (SER), were compared with those of 100 patients without SER. There were no significant differences in age and sex distribution or in clinical and coronary angiographic findings between the two groups. There was, however, a significantly lower prevalence of pathologic Q or QS patterns in the anterior leads of the ECG in the group with SER. SER occurred more frequently in segments with well-preserved systolic contraction and was confined to the anterolateral segments in the great majority of the patients (80%). An inverse correlation was found between SER and geographically related critical coronary artery stenosis.

Lessons from in vitro models of small, irregular, multiple and tunnel-like stenoses relevant to clinical stenoses of valves and small vessels.

This review examines data on the accuracy of the simplified Bernoulli equation for quantitation of pressure drops across small, irregular, multiple and tunnel-like stenoses. This information is drawn from in vitro models of such cardiovascular stenoses and explores the limits of this simplification as they affect accuracy in special situations. Within the physiologic range, discrete small and irregular stenoses present no problems for the measurement of pressure drops using the simplified Bernoulli equation. Multiple side by side orifices of different dimension also give reasonable data using this approach. Tunnel-like stenoses of very small diameter and finite length produce underestimation of the true pressure drop through the stenosis when the simplified Bernouli equation is used. This underestimation is primarily due to neglect of the energy consumed by viscous friction in this situation. These considerations are especially pertinent to the problem of measuring pressure gradients across coronary vessels to assess their clinical significance as well as the adequacy of angioplasty and other intravascular interventional techniques. Because this area needs further exploration, some discussion of in vitro models as such as included.

Unusual electrocardiogram in hypertrophic cardiomyopathy.

Electrocardiographic criteria of right ventricular hypertrophy were found in a 17-year-old male with nonobstructive hypertrophic cardiomyopathy involving the left ventricle. Right ventricular hypertrophy pattern is a rare electrocardiographic abnormality in patients with hypertrophic cardiomyopathy and the presence of Q waves in leads V5-V6 could be helpful in differentiating this syndrome from true right ventricular hypertrophy.

Anomalous origin of the coronary arteries.

The incidence and the clinical significance of various forms of anomalous aortic origin of coronary arteries are not well known. Among 2,000 consecutive patients who underwent selective coronary aretriography, 11 had such anomalies (0.55%). Two patients with atresia of the left main ostia developed ischemic symptoms at the ages of thirty-five and fifty-two, and both benefitted from coronary bypass graft operation. In other forms of anomalies the presence of ischemic symptoms was also associated with atherosclerotic stenosis (7 patients) or with constricting muscle bridge (1 patient).