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.     

Transient Hypertrophic Obstructive Cardiomyopathy During Pregnancy

Hypertrophic obstructive cardiomyopathy (HOCM) is a primary myocardial disease with typical echocardiography features of asymmetric septal hypertrophy and evidence of left ventricular outflow tract obstruction. The natural history of HOCM is characterized by a slow progression of symptoms and a significant annual mortality rate. We report an unusual case of transient HOCM during pregnancy with evidence of total resolution postpartum.
hypertrophic cardiomyopathy, pregnancy, idiopathic hypertrophic subaortic stenosis, two-dimensional echocardiography, Doppler echocardiography     

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.     

Formulating causal questions and principled statistical answers

Although review papers on causal inference methods are now available, there is a lack of introductory overviews on what they can render and on the guiding criteria for choosing one particular method. This tutorial gives an overview in situations where an exposure of interest is set at a chosen baseline (“point exposure”) and the target outcome arises at a later time point. We first phrase relevant causal questions and make a case for being specific about the possible exposure levels involved and the populations for which the question is relevant. Using the potential outcomes framework, we describe principled definitions of causal effects and of estimation approaches classified according to whether they invoke the no unmeasured confounding assumption (including outcome regression and propensity score-based methods) or an instrumental variable with added assumptions. We mainly focus on continuous outcomes and causal average treatment effects. We discuss interpretation, challenges, and potential pitfalls and illustrate application using a “simulation learner,” that mimics the effect of various breastfeeding interventions on a child's later development. This involves a typical simulation component with generated exposure, covariate, and outcome data inspired by a randomized intervention study. The simulation learner further generates various (linked) exposure types with a set of possible values per observation unit, from which observed as well as potential outcome data are generated. It thus provides true values of several causal effects. R code for data generation and analysis is available on www.ofcaus.org , where SAS and Stata code for analysis is also provided.     

Effect of Successful Coronary Angioplasty on the Signal-Averaged Electrocardiogram

The effect of successful coronary artery angioplasty on the signal-averaged electrocardiogram (SAECG) was examined in 50 patients (41 men, 9 women, aged 55 +/- 8 years) with stable (26 patients) or unstable angina (24 patients) and good overall left ventricular function (ejection fraction = 55% +/- 8%). The SAECG was recorded before and within 24-48 hours after the angioplasty and was filtered at 40-250 Hz, with 250 beats averaged. The noise level averaged 0.57 +/- 0.15 microV before and 0.56 +/- 0.17 microV after the procedure. There was no overall significant difference between pre- and postangioplasty SAECGs. Subgroup analysis showed that 14 patients had a significant increase of the root mean square voltage of the last 40 msec of the filtered QRS that was independent of noise level changes, previous myocardial infarction, stable or unstable angina status, positive or negative baseline SAECG, or vessel being dilated. Eleven patients (22%) had late potentials at baseline, of whom four (36%) lost them after angioplasty, while one patient developed them after the procedure, all due to root mean square voltage changes. Thus, successful angioplasty exerted no significant overall effect on the SAECG, suggesting that the substrate of late potentials was not grossly altered by the procedure in our patients. However, there appear to be some patients, constituting approximately one third of this study population, who derive a favorable influence on the SAECG from angioplasty, a subgroup that needs to be further defined in future studies.     

Patterns of alcohol consumption and related problems in the general population of Greece

This paper focuses on patterns of alcohol consumption and related problems, based on a nation-wide home survey sample of 4290 respondents aged 12–64 years. The prevalence of lifetime, past year and past month alcohol use, as well as levels of quantity of alcohol consumed and the reported alcohol-related problems, are presented. Frequency and quantity of consumption increases as age increases. Males were found to drink alcohol more frequently and in higher quantities than females. A higher proportion of young adults reported alcohol-related problems, in comparison to the other age groups. Regional variations in the frequency of consumption of alcohol were observed. However, no differences were found in the geographic distribution of persons of all age groups reporting alcohol-related problems. Respondents of all groups with two or more alcohol related problems expressed a high number of dysphoric and depressive symptoms. Finally, a stepwise discriminant analysis revealed certain socio-demographic, familial, psychological and medical factors to discriminate optimally the “problem” and “non-problem” drinkers in both adolescent and adult age groups.     

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.