Deniz Kumbasar

Assessment of left ventricular diastolic function with Doppler tissue imaging: Effects of preload and place of measurements

Mitral inflow velocities are widely used for the evaluation of left ventricular (LV) diastolic function. However, they are closely affected by other factors such as preload. The purpose of this study was to evaluate the usefulness of tissue Doppler velocities obtained from the mitral annulus for the evaluation of ventricular relaxation in patients under different loading conditions. We also evaluated the effect of preload at different sides on the mitral annulus. The study population consisted of 62 consecutive patients (38 male, 24 female with a mean age of 42 ± 13 years) who have undergone hemodialysis. Both mitral inflow velocities (E wave, A wave, E wave deceleration time and isovolumetric relaxation time) and mitral annulus tissue Doppler velocities (E′, A′) from the septal, lateral, anterior, posterolateral and inferior sides of the mitral annulus were measured immediately before and after hemodialysis. Mitral inflow E and A wave velocities and E/A ratio decreased significantly (p < 0.001, p = 0.007, p < 0.001, respectively) after hemodialysis. Mitral annulus E′ wave velocities and E′/A′ ratios obtained from five different sides of the annulus also changed significantly (p < 0.001 for all); however, there was no change in the A′ wave velocity (p > 0.05 for all) after hemodialysis. The decrease in E wave and E/A ratio in mitral inflow measurements and E′ velocities and E′/A′ ratios in tissue Doppler measurements were correlated with the amount of fluid extracted (for mitral inflow E wave, r = 0.392, p = 0.002 and E/A ratio, r = 0.280 and p = 0.027; for lateral side E′, r = 0.329, p = 0.009 and E′/A′ ratio, r = 0.286, p = 0.04; for septal side E′, r = 0.376, p = 0.003 and E′/A′ ratio, r = 0.297, p = 0.019; for anterior side E′, r = 0.342, p = 0.007 and E′/A′ ratio, r = 0.268, p = 0.035; for posterolateral side E′, r = 0.423, p = 0.001 and E′/A′ ratio, r = 0.343, p = 0.007; and for inferior side E′, r = 0.326, p = 0.01 and E′/A′ ratio, r = 0.278, p = 0.029). We conclude that mitral annular velocities obtained by tissue Doppler are preload dependent parameters for the evaluation of LV diastolic function.

Hyperhomocysteinemia and Restenosis

Objective This study was undertaken to assess the effect of plasma homocysteine level on angiographic restenosis 6 months after coronary angioplasty. Methods The plasma homocysteine level was measured in 100 consecutive patients at the time of coronary angioplasty, 56 patients who attended a 6-month follow-up angiogram being enrolled to the study; the 44 patients without a control coronary angiogram were not enrolled. Patients with and without angiographic restenosis were designated as groups A (n = 34) and B (n = 22) respectively. Results The baseline demographic (groups A and B), angiographic (groups A and B) and procedural characteristics were similar in both groups. The mean plasma homocysteine level (SD) was 15.2 (7.7) and 11.1 (2.5) μmol/l in groups A and B respectively (P = 0.007; 95% CI −6.9 to −1.1). With respect to the plasma homocysteine level, the upper and the lower thirds were compared by binary logistic regression (the lower third homocysteine level being < 10.6 μmol/l and the upper third homocysteine level > 14.1 μmol/l). The angiographic restenosis rate for the lower and upper tertiles was 47.4% and 89.5% respectively (P = 0.01; OR = 9.4; 95% CI 1.6−52.7). After adjustment for age and sex, the statistical significance did not change (P = 0.013; OR = 9.43; 95% CI 1.6-54.9). Even after adjustment for age, sex, smoking, hypertension, hypercholesterolemia, and diabetes mellitus, there was a statistically significant difference between the upper and lower tertiles (P = 0.008; OR = 41.3; 95% CI 2.6-635). Conclusion Increased plasma homocysteine level and diabetes mellitus were independent risk factors for angiographic restenosis after percutaneous transluminal coronary angioplasty and coronary stenting.

Good Collaterals Predict Viable Myocardium

The authors undertook this study to see whether highly developed coronary collaterals at an area shed by a totally occluded coronary artery predicts myocardial viability. Percutaneous coronary intervention (PCI) of a totally occluded coronary artery has been debated since its introduction. It is recommended to search for viable myocardium before opening a totally occluded coronary artery; however, there is no practical yet sensitive method of assessing myocardial viability in the catheterization laboratory. Forty-seven consecutive patients (12 women, 25.5%; 35 men, 74.5%), each with 1 totally occluded coronary artery, were prospectively enrolled to the study. After the diagnostic coronary angiography, all patients underwent dobutamine stress echocardiography to determine viable myocardium at the territory of the totally occluded coronary artery, and the status of angiographic coronary collaterals was assessed. Patients were then divided into 2 groups according to the presence (Group A) or absence (Group B) of viable myocardium by stress echocardiography. Eighteen patients (38.3%) had viable myocardium (Group A) in the area shed by the totally occluded coronary artery and 29 patients (61.7%) had nonviable myocardium (Group B). The incidences of significant coronary collateral circulation to the viable (Group A) and nonviable (Group B) areas were 66.7% (12 patients) and 20.7% (6 patients), respectively (p = 0.002). Logistic regression analysis was used to evaluate the independent factors for viable myocardium, and only significant coronary collateral circulation was found to be an independent factor for the detection of viable myocardium (p = 0.006, OR 16.7, 95% CI 2.25 to 124.4). The sensitivity and specificity of good collateral circulation for the detection of viable myocardium were 75% and 65.7%, respectively. The positive predictive and negative predictive values of the good coronary collateral circulation in detecting viable myocardium were 75% and 79%, respectively. The authors conclude that good coronary collaterals have a high sensitivity and positive predictive value for the prediction of viability as shown by dobutamine echocardiography, and only by assessing the coronary collateral circulation can one decide for percutaneous coronary revascularization, if not for coronary artery bypass surgery.

Association between the dosage and duration of statin treatment with coronary collateral development.

BackgroundThe coronary collateral circulation is an alternative source of blood supply to myocardium in the presence of advanced coronary artery disease and the therapeutic promotion of collateral growth appears to be a valuable treatment strategy in these patients. Although it has been shown in in-vivo studies that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) promote vasculogenesis and accelerate coronary collateral development in ischemic tissues, there are discordant results in clinical studies. Our aim was to investigate the effect of statin therapy, including dosage and duration of treatment, on coronary collateral growth in patients with advanced coronary artery disease. MethodsStudy population consisted of 400 (306 men, with the mean age of 62±10 years) consecutive patients who have undergone clinically indicated coronary angiography and had at least one major coronary artery stenosis of ≥95%. Coronary collaterals were graded from 0 to 3 according to the Cohen–Rentrop method and patients with grade 0–1 collateral development were regarded as having poor collateral and patients with grade 2–3 collateral development were regarded as having good collateral. ResultsAmong 400 patients, 196 (48%) were on statin therapy. Patients with good collateral score were more likely to have stable angina pectoris as clinical presentation (P<0.001), and were on statin therapy (P=0.001), and have multivessel disease (P=0.003). Statin therapy for less than 3 months had no effect on collateral development (P=0.19); however, patients who were on statin therapy for more than 3 months had significantly better collateral development (P=0.002). Statin therapy had no effect on coronary collateral development in patients having <10 mg atorvastatin-equivalent dose (P=0.13); however, patients having ≥10 mg atorvastatin-equivalent dose had better collateral development (P<0.001). Diabetes mellitus was the only negative predictor for coronary collateral formation (P=0.03). On multivariate analysis, stable angina pectoris [odds ratio 2.88, 95% confidence interval (1.8–4.7), P<0.001], statin therapy with ≥10 mg atorvastatin-equivalent dose [odds ratio 2.06, 95% confidence interval (1.3–2.6), P<0.001] and having multivessel disease [odds ratio 1.86, 95% confidence interval (1.16–3), P=0.01] were found to be associated with rich collateralization. ConclusionStatin therapy (≥10 mg atorvastatin-equivalent dose), stable angina pectoris and having multivessel disease are associated with enhanced coronary collateral development in patients with advanced coronary artery disease.

Facilitation of radial artery cannulation by periradial subcutaneous administration of nitroglycerin.

PURPOSE To determine whether subcutaneous administration of nitroglycerin mixed with local anesthetic agent results in effective vasodilation of the radial artery, and whether this technique improves access time and decreases complications. MATERIALS AND METHODS This prospective study consisted of two consecutive investigations. In the first (n = 30), only local anesthetic agent (prilocaine 2%) was injected into one arm, and local anesthetic agent plus 500 microg nitroglycerin was injected into the other arm. Radial artery diameters before and after injections were measured by ultrasonography. In the second, 33 patients received local anesthetic agent (prilocaine 2%) plus 500 microg nitroglycerin (group A) and 30 received only local anesthetic agent (group B) to determine whether the addition of nitroglycerin would improve radial artery access time, duration of angiography, perception of arterial pulse (ie, pulse score), number of punctures before successful cannulation, and complication rates. RESULTS In the first investigation, radial artery diameter increased significantly in the nitroglycerin-treated arm (2.3 mm +/- 0.4 vs 2.9 mm +/- 0.5; P = .05). In the second, there were no significant differences between groups with respect to age, sex, duration of angiography, and number of punctures before cannulation. However, the pulse score increased and radial artery access time improved significantly after addition of nitroglycerin (79% vs 10% [P < .001] and 75 sec +/- 47 vs 132 sec +/- 100 [P = .005], respectively). Radial artery spasm and thrombosis were less frequently observed in group A, albeit to an insignificant extent (P = .39 and P = .49, respectively). CONCLUSIONS Subcutaneous administration of nitroglycerin significantly increased radial artery diameter, which can lead to facilitation of catheterization of the radial artery for arteriography and interventions.

Hyperhomocysteinaemia and coronary artery disease in the Turkish population

Objective — Many studies have demonstrated a strong association between elevated plasma total homocysteine (Hcy) levels and vascular disease.The objective of this study was to examine the relation between homocysteine levels and coronary artery disease in Turkish patients. Methods and results — In this study plasma homocysteine levels were measured in control and patient groups. A significant coronary artery lesion was defined as a stenosis of ≥70% as shown by coronary angiography and determined by on-line quantitative measurements; treatment was by coronary angioplasty. Total plasma Hcy level was measured before the coronary intervention. Plasma homocysteine levels were measured by an HPLC method in patients with a definite diagnosis of coronary artery disease and compared with age- and sex-matched controls. Patients with coronary artery disease had significantly higher mean homocysteine concentrations than control subjects (geometric mean ± 95% CI: 12.5±1.1 μmol/l vs. 8.60±1.07 μmol/l, p > 0.001). Eighty-three (59%) members of the patient group and 14 (21%) members of the control group had plasma homocysteine concentrations above the 11.3 μmol/l, which represents the concentration which includes the uppermost quintile of the control group distribution (odds ratio 4.35, 95% CI; 2.1-8.94). Conclusion — Results of this study indicate that high plasma levels of homocysteine in Turkish subjects are associated with coronary artery disease. Our data suggest that focusing public health initiatives on this issue may reduce the high prevalence of cardiovascular disease in the Turkish population.OBJECTIVE Many studies have demonstrated a strong association between elevated plasma total homocysteine (Hcy) levels and vascular disease. The objective of this study was to examine the relation between homocysteine levels and coronary artery disease in Turkish patients. METHODS AND RESULTS In this study plasma homocysteine levels were measured in control and patient groups. A significant coronary artery lesion was defined as a stenosis of > or = 70% as shown by coronary angiography and determined by on-line quantitative measurements; treatment was by coronary angioplasty. Total plasma Hcy level was measured before the coronary intervention. Plasma homocysteine levels were measured by an HPLC method in patients with a definite diagnosis of coronary artery disease and compared with age- and sex-matched controls. Patients with coronary artery disease had significantly higher mean homocysteine concentrations than control subjects (geometric mean +/- 95% CI: 12.5 +/- 1.1 micromol/l vs. 8.60 +/- 1.07 micromol/l, p<0.001). Eighty-three (59%) members of the patient group and 14 (21%) members of the control group had plasma homocysteine concentrations above the 11.3 micromol/l, which represents the concentration which includes the uppermost quintile of the control group distribution (odds ratio 4.35, 95% CI; 2.1-8.94). CONCLUSION Results of this study indicate that high plasma levels of homocysteine in Turkish subjects are associated with coronary artery disease. Our data suggest that focusing public health initiatives on this issue may reduce the high prevalence of cardiovascular disease in the Turkish population.

Intravascular volume dependency of left ventricular mass calculation by two-dimensional guided M-mode echocardiography

BACKGROUND Increased left ventricular mass (LVM) is an independent risk factor for cardiovascular morbidity and mortality, and may be used for risk stratification. Two-dimensional echocardiography, the most commonly used technique for estimation of LVM, uses the third power of the left ventricular internal diameter (LVID) for the calculation. OBJECTIVES To determine whether a decrease in intravascular volume after dialysis may cause inaccurate estimation of LVM by echocardiography. METHODS Thirty-eight patients undergoing hemodialysis due to chronic renal failure constituted the study group (14 women [37%] and 24 men [63%], mean age +/- SD 38.7+/-10.9 years). LVID, and interventricular and posterior wall thicknesses were measured by two-dimensionally guided M-mode echocardiography. Stroke volume and cardiac output were calculated using left ventricular outflow tract diameter and the pulsed-wave Doppler time-velocity integral obtained from left ventricular outflow tract. LVM was calculated by using Devereuxs formula, and was indexed for body surface area and height. All echocardiographic parameters were measured or calculated before and after dialysis (on the same day), and then compared. RESULTS There were no significant changes in wall thickness; however, LVID, LVM, the LVM/body surface index and the LVM/height index significantly decreased after dialysis (P<0.001 for each parameter). There was a significant correlation between the change in LVID and the change in LVM (P<0.001, r=0.59). Stroke volume and cardiac output also decreased significantly after hemodialysis (P<0.001 for each parameter). CONCLUSIONS Intravascular volume-dependent change in LVID causes inaccurate estimation of LVM, so volume status should be kept in mind, especially in serial assessment of LVM.

The relation between transmitral early filling wave deceleration time and the recovery of atrial contractility after electrical cardioversion of atrial fibrillation.

BACKGROUND Electrical cardioversion of atrial fibrillation (AF) to sinus rhythm is associated with transient left atrial dysfunction and this phenomenon may lead to thrombus formation and embolic stroke. Delay of atrial mechanical function recovery may be related to ventricular diastolic function. OBJECTIVE This study examined the effects of left ventricular diastolic function as well as the multiple clinical factors on the recovery of atrial systolic function after cardioversion for atrial fibrillation. METHODS A total of 44 patients (28 male, 16 female, 61+/-18 years) with chronic AF (> or =1 month) underwent electrical cardioversion. Deceleration time of early filling wave (pre-CV EDT) on transmitral inflow obtained by using Doppler echocardiography before cardioversion and serial transmitral inflow Doppler variables were recorded through a 1 week study period in all patients. Various clinical (age, gender, the duration of AF) and echocardiographic variables (pre-CV EDT, left atrial dimension, left ventricular ejection fraction) were tested for an association with peak atrial filling wave velocity (VA) on day 1, 3 and 7 after cardioversion. RESULTS EDT measured before cardioversion had a strong linear correlation with peak VA on every echocardiographic evaluation after cardioversion (Regression coefficient (R)=0.69, P<0.001; R=0.78, P<0.001 and R=0.83, P<0.001, on day 1, day 3 and day 7, respectively). The effect of left ventricular ejection fraction on peak VA was weaker than those of EDT. The duration of AF showed an inverse association with the recovery of atrial function, but this lost on multivariate analysis. None of the other parameters significantly correlated with peak VA after cardioversion. CONCLUSION The recovery of atrial mechanical function after cardioversion, as assessed by peak VA on transthoracic Doppler echocardiography is mainly associated with the left ventricular diastolic function as measured by EDT, whereas the left ventricular systolic function relatively a small effect on this outcome. The duration of AF does not have any association with peak VA, possibly if it is chronic.

Effect of hypertension on coronary remodeling patterns in angiographically normal or minimally atherosclerotic coronary arteries: an intravascular ultrasound study.

Whether there is any particular role of hypertension in remodeling process has not been completely understood yet. The aim of this study was to assess the association between hypertension and remodeling patterns in normal or minimally atherosclerotic coronary arteries. Seventy-nine patients who were free of significant coronary atherosclerosis were divided into two groups according to the absence (n = 39) or presence (n = 40) of hypertension; and standard intravascular ultrasound examination was performed in 145 segments. To determine the remodeling pattern in early atherosclerotic process, patients were also analyzed according to the level of plaque burden at the lesion site after the analysis of remodeling patterns. Positive remodeling was more prevalent in the hypertensive group (52.5% vs. 12.8%; P < .001) whereas negative remodeling was more common in diabetic patients (53.6% vs. 27.4%; P = .03). Mean remodeling index was 1.04 for hypertensives and 0.96 for normotensives (P = .03). There were no correlations between remodeling patterns and other risk factors such as age, family history, and hypercholesterolemia. Early atherosclerotic lesions (<30%) exhibited more negative remodeling characteristics while intermediate pattern was observed more frequently in patients with high plaque burden (P = .006 and .02, respectively). Positive remodeling showed no association in this context (P = .07). This study demonstrated that minimal atherosclerotic lesions in hypertensives had a tendency for compensatory arterial enlargement. Positive remodeling may result from local adaptive processes within vessel wall or hemodynamic effects of blood pressure itself.

Effect of Coronary Collateral Circulation on Exercise Stress Test

In this study, patients who have recovery-only ST segment depression in exercise stress test were chosen. It is proposed that coronary collateral circulation could improve with stress-increased coronary perfusion, and accordingly, patients with recovery-only ST segment depression were evaluated by coronary angiography for grading the coronary collateral circulation. Twenty-one men and five women were assigned to the study group. Sixteen men and two women who had exercise-induced ST segment depression were assigned to the control group. Age and gender of both groups were not statistically different (p > 0.05) . The reason for terminating the exercise stress test was chest pain in two of 26 patients in the study group versus 15 of 18 in the control group (p < 0.001 ) . In both groups coronary collateral frequency and grade were directly correlated with the severity of the coronary artery disease (p < 0.001 in the study group, and p < 0.05 in the control group). When both groups were compared for the frequency of significant coronary collateral circulation, 14 of 26 patients in the study group versus 4 of 18 patients in the control group had significant coronary collateral circulation (p=0.035). The authors conclude that recovery-only ST segment depression correlates well with the frequency of significant coronary collateral circulation, and coronary collaterals may prevent myocardial ischemia during exercise.