Distensibility of the ascending aorta: comparison of invasive and non-invasive techniques in healthy men and in men with coronary artery disease

Distensibility of the ascending aorta, measured non-invasively,was compared with values obtained by invasive techniques in46 males (30 patients with coronary artery disease and 16 age-matchednormal subjects). Aortic diameters were measured at a level3 cm above the aortic valve using both echocardiographic andangiographic techniques. Aortic distensibility was calculatedfrom the aortic diameters and aortic pressure or brachial arterypressure using the formula: 2 x (change in aortic diameter)/(diastolic aortic diameter) x (change in aortic pressure).Distensibility of the ascending aorta determined non-invasivelywas closely related to that obtained by direct measurements(r = 0.949, P<0.001). Patients with coronary artery diseasehad similar pressures, but markedly lower distensibility thannormal subjects, as shown by both invasive and non-invasivetechniques. The results indicate that aortic distensibilityin patients with coronary artery disease can be obtained non-invasivelywith a high degree of accuracy.     

Differential Effect of Biventricular and Right Ventricular DDD Pacing on Coronary Flow Reserve in Patients With Ischemic Cardiomyopathy

CRT and Coronary Flow Reserve. Background: Cardiac resynchronization therapy (CRT) has become a mainstay in heart failure management. There are also indications that upgrading of existing pacemakers to CRT systems may be of benefit. The aim of this study was to assess the effect of biventricular (BiV), compared with right ventricular (RV), pacing, on coronary flow reserve (CFR), in patients with ischemic cardiomyopathy. Methods and Results: From our database of heart failure patients implanted with BiV pacemakers, 20 patients (10 responders and 10 non‐responders to CRT) were randomly selected. Left anterior descending artery coronary flow reserve was measured invasively, under BiV and RV pacing, using intracoronary adenosine to induce hyperemia. In all the 20 patients, there was a significant difference in the pairwise comparison between CFR recorded during BiV and RV pacing (mean difference 0.15, 95% confidence interval 0.07–0.23, P = 0.001). When comparing responders to non‐responders, there was a significant difference as to the effect of BiV, compared with RV, pacing on CFR: mean difference (BiV minus RV CFR) was 0.26 ± 0.06 (95% confidence interval 0.13–0.39; P = 0.002), while in non‐responders the difference was 0.04 ± 0.03 (95% confidence interval ?0.02 to 0.10; P = 0.168). Conclusion: BiV pacing is overall associated to higher CFR, compared with RV DDD pacing. This difference is almost exclusively attributable to the beneficial effect of CRT on coronary flow reserve in CRT‐responders. This effect may contribute to the beneficial action of resynchronization in the failing heart and can be viewed in the context of reports of the usefulness of upgrading RV pacemakers to CRT systems. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1233‐1239, November 2010)     

Carotid Sinus Hypersensitivity in Patients Undergoing Coronary Arteriography:

Carotid Sinus Hypersensitivity and Atherosclerosis. Introduction: The purpose of the present investigation was to study the precise relationship between carotid sinus hypersensitivity (CSH) and both the severity of carotid atherosclerosis and the extent of coronary artery disease in patients who were referred for evaluation for suspected ischemic heart disease.
Methods and Results: Duplex echocardiography and coronary angiography were used to assess carotid and coronary artery atherosclerosis in 130 consecutive patients. Carotid sinus stimulation was performed before coronary arteriography with simultaneous recordings of the ECG and aortic pressure. Coronary artery disease was present in 103 patients (79%). Thirty patients (23.08%) had one-vessel disease (1-VD), 31 (23.85%) had 2-VD, 29 (22.31%) had 3-VD, and 13 patients (10%) had left main coronary artery disease. Carotid artery atherosclerosis was present in 100 patients (76.92%) and carotid disease (diameter stenosis ≥ 50%) was present in 24 patients (18.46%). CSH was found in 33 patients (25%). The incidence of CSH was 9% in patients with carotid stenosis 1%-15%, 17% in patients with stenosis 16%-49%, 85% in patients with stenosis 50%-79%, and 100% in patients with stenosis ≥ 80%. The incidence of CSH was 11%, 17%, 23%, 34%, and 62% in patients with no VD, 1-VD, 2-VD, 3-VD, and left main coronary artery disease, respectively. Stepwise multiple logistic regression analysis revealed that carotid disease and left main coronary artery disease were the most significant determinants of CSH (P < 0.001 and P = 0.013, respectively).
Conclusion: The incidence of CSH increased in proportion to the severity of carotid and coronary atherosclerosis. These data provide evidence that CSH is closely related to severe carotid atherosclerosis or left main coronary artery disease in patients being evaluated for suspected ischemic heart disease.     

On the explanation of the M-mode echocardiographic image of an atrial myxoma

Two experimental models were used to simulate the motion ofa valve leaflet and atrial myxoma in order to investigate theechocardiographic images produced. Both support the view thatan endogenous contrast effect, i.e. surfaces of different acousticdensities that are produced as a result of turbulence in a fluidmedium and give rise to echo images, contributes to the echocardiographicM-mode appearance of the atrial mass.     

Accomplishments and Perspectives with Retrograde Nontransseptal Balloon Mitral Valvuloplasty

Retrograde nontransseptal balloon mitral valvuloplasty (RNBMV) is a transarterial technique of mitral valvuloplasty, developed with the aim to avoid complications associated with transseptal catheterization. Between April 1988 and December 1999, RNBMV has been attempted in 393 patients with symptomatic mitral stenosis (aged 44 ± 11 years, 322 women, mean echocardiographic score 7.7 ± 1.9) at the University of Athens, Greece. The procedure was completed in 392 cases. Technical success (gain in mitral valve area ≥ 50% with final mitral valve area ≥ 1.5 cm², and absence of postprocedural mitral regurgitation grade > 2+) was achieved in 344 (87.5%) patients. Unfavorable predictors for immediate outcome included the echocardiographic score (P < 0.001). male gender (P = 0.005), and preprocedural mitral regurgitation (P = 0.003). Complications included death (0.3%), severe mitral regurgitation (3.1%), and femoral artery injury (0.8%). No cases of cardiac peqoration or tamponade have occurred with RNBMV. Patients with a successful immediate outcome were followed clinically for 4.8 ± 2.8 years (maximum 12 years). Event-free (freedom from cardiac death, mitral valve replacement, redo valvuloplasty, and recurrence of NYHA Class > II) survival rates at 1, 2, 5, and 12 years post-RNBMV were 99.7 ± 0.3%, 96.1 ± 1.1%, 84.7 ± 2.2%. and 67.6 ± 4.8%, respectively. The echocardiographic score (P < 0.001) and the postprocedural mitral valve area (P < 0.001) were significant independent predictors of long-term outcome following RNBMV. Experience with RNBMV has fulfilled expectations regarding lowering of the risk of occurrence of specific cardiac complications encountered during mitral valvuloplasty, and reveals this approach as a safe and efficient alternative to the more commonly used antegrade technique.     

Echocardiographic assessment of atrial tumour size and endogeneously generated contrast imagesAn experimental study

Experimental models, in vitro and in vivo, were designed tosimulate the motion of an atrioventricular valve leaflet andan atrial tumour. Cross-sectional echocardiography was usedto investigate any changes in apparent tumour size related toits motion. Both parts of the study suggest that endogenouscontrast, due to surfaces of different acoustic densities generatedaround the rapidly moving tumour, contributes to the echo-graphicpattern of the tumour. Thus, during diastole, the echo-masscloud is greater than the real size of the tumour. The echocardiographicand actual size of the tumour may be identical only in ventricularsystole when the blood flow around the atrial tumour is greatlydecreased.