Improved posterobasal segment function after thrombolysis is associated with decreased incidence of significant mitral regurgitation in a first inferior myocardial infarction

Objectives. This study was designed to investigate the association between wall motion abnormalities and the occurrence of ischemic mitral regurgitation in patients with a first inferior or posterior myocardial infarction and to reassess the role of thrombolytic treatment in these patients.

Background. We previously demonstrated that thrombolytic therapy reduces the incidence of significant mitral regurgitation in patients with a first inferior myocardial infarction, but the mechanisms responsible for this decrease were not clear.

Methods. Wall motion score on two-dimensional echocardiography (16 segments) and mitral regurgitation grade (0 to 3) on Doppler color flow imaging were assessed in 95 patients (in 47 after thrombolysis) at 24 h, 7 to 10 days and 1 month after myocardial infarction. Significant mitral regurgitation was defined as moderate or severe (grade 2 or 3).

Results. Multivariate analysis revealed that the presence of an advanced wall motion abnormality of the posterobasal segment of the left ventricle was the most significant independent variable associated with significant mitral regurgitation: odds ratio (OR) 15.0, 90% confidence interval (CI) 1.4 to 165.6 at 24 h; OR 2.8, CI 0.9 to 9.3 at 7 to 10 days; OR 4.2, CI 1.2 to 11.4 at 1 month. Thrombolysis reduced the prevalence of advanced wall motion abnormalities in the posterobasal segment at 24 h (55% vs. 75%, OR 0.5, CI 0.2 to 0.99), 7 to 10 days (44% vs. 73%, OR 0.3, CI 0.1 to 0.7) and 1 month (36% vs. 56%, OR 0.4, CI 0.2 to 0.9).

Conclusions. There is a strong association between advanced wall motion abnormalities in the posterobasal segment and significant mitral regurgitation. In this study group, thrombolysis reduced the prevalence of advanced wall motion abnormalities in the posterobasal segment and thereby reduced the incidence of significant mitral regurgitation.     

Influence of ethanol on the delivery of intravenous nitroglycerin solutions

Summary In order to evaluate the surface tension lowering effect of ethanol in intravenous nitroglycerin solutions of varying concentrations, drop size was measured in intravenous transfusion sets that should deliver 60 drops/ml.Ethanol 5% solutions led to a significant decrease in drop volume and a concomitant increase in the number of drops per unit volume, up to 79 drops/ml were observed.The surface tension lowering effect may account for decreases of up to 25% in delivered nitroglycerin when drop counting infusion pumps are used, and may be a factor in the development of apparent tolerance to intravenous nitroglycerin.     

Cells, scaffolds, and molecules for myocardial tissue engineering

Unlike heart valves or blood vessels, heart muscle has no replacement alternatives. The most challenging goal in the field of cardiovascular tissue engineering is the creation/ regeneration of an engineered heart muscle. Recent advances in methods of stem cell isolation, culture in bioreactors, and the synthesis of bioactive materials promise to create engineered cardiac tissue ex vivo. At the same time, new approaches are conceived that explore ways to induce tissue regeneration after injury. The purpose of our review is to describe the principles, status, and challenges of myocardial tissue engineering with emphasize on the concept of in situ cardiac tissue engineering and regeneration.     

Polyglandular autoimmune syndrome, type 2

We have described two patients with Addison's disease and associated endocrinopathies, a condition termed polyglandular autoimmune (PGA) syndrome, type 2. One of our patients also had autoimmune hypothyroid disease, and the other had premature gonadal failure and Hashimoto's thyroiditis. This syndrome shows that glandular disorders tend to occur together. It has been suggested that an HLA-associated genetic predisposition coupled with environmental factors triggers an autoimmune process resulting in glandular hypofunction or hyperfunction. We stress the necessity for evaluation of every individual with idiopathic Addison's disease for associated endocrinopathies.     

Hyperkalemic left bundle branch block and hyporeninemic hypoaldosteronism (hyperkalemic left bundle branch block)

A 70-year-old woman was admitted to the intensive coronary care unit with suspected myocardial infarction. During the follow-up period, the patient twice developed left bundle branch block, which was shown to be related to high serum potassium levels secondary to hyporeninemic hypoaldosteronism and moderate renal failure.     

A database analysis method identifies an endogenous trans-acting short-interfering RNA that targets the Arabidopsis ARF2, ARF3, and ARF4 genes

Two classes of small RNAs, microRNAs and short-interfering RNA (siRNAs), have been extensively studied in plants and animals. In Arabidopsis, the capacity to uncover previously uncharacterized small RNAs by means of conventional strategies seems to be reaching its limits. To discover new plant small RNAs, we developed a protocol to mine an Arabidopsis nonannotated, noncoding EST database. Using this approach, we identified an endogenous small RNA, trans-acting short-interfering RNA-auxin response factor (tasiR-ARF), that shares a 21- and 22-nt region of sequence similarity with members of the ARF gene family. tasiR-ARF has characteristics of both short-interfering RNA and microRNA, recently defined as tasiRNA. Accumulation of trans-acting siRNA depends on DICER-LIKE1 and RNA-DEPENDENT RNA POLYMERASE6 but not RNA-DEPENDENT RNA POLYMERASE2. We demonstrate that tasiR-ARF targets three ARF genes, ARF2, ARF3/ETT, and ARF4, and that both the tasiR-ARF precursor and its target genes are evolutionarily conserved. The identification of tasiRNA-ARF as a low-abundance, previously uncharacterized small RNA species proves our method to be a useful tool to uncover additional small regulatory RNAs.     

Functional capacity impairment in patients with coronary artery disease: prevalence, risk factors and prognosis

BACKGROUND: Some patients developing heart failure and functional capacity impairment have no history of myocardial infarction (MI), and stable angina pectoris is their principal clinical manifestation of coronary artery disease (CAD). The present study was aimed to evaluate the outcome of CAD-related functional capacity impairment in patients with and without a history of MI over a 7.7-year follow-up. METHODS: The study sample comprised 14,283 coronary patients aged 45-74 years, screened for participation in the Bezafibrate Infarction Prevention study. The presence of NYHA functional class II was defined as mild functional capacity impairment and the presence of NYHA functional class III-IV was defined as advanced functional capacity impairment. RESULTS: The patients were divided in two groups: (1) those with a history of MI, 10,307 patients, who formed three subgroups: NYHA I 7,551 patients (73.3%); NYHA II 2,176 patients (21.1%); NYHA III + IV 580 patients (5.6%), and (2) those without a history of MI, 3,976 patients, who also formed three subgroups: NYHA I 2,744 patients (69.0%); NYHA 981 patients (24.7%); NYHA III + IV 251 patients (6.3%). Multivariate analysis identified a history of MI as a consistent predictor of increased all-cause and cardiac mortality for patients with NYHA I, II and III + IV subgroups with escalating significance for patients with advanced functional capacity impairment: hazard ratios of 1.55 (95% CI 1.36-1.75), 1.56 (95% CI 1.30-1.86) and 1.72 (95% CI 1.24-2.40) for all-cause and 1.93 (95% CI 1.60-2.33), 1.73 (95% 1.35-2.20) and 3.22 (95% CI 1.87-5.54) for cardiac mortality, respectively. CONCLUSIONS: The prevalence of low functional capacity is similar among coronary patients with and without a history of MI, but their long-term survival differs substantially in favor of the latter. Therefore, two different types of CAD-related advanced functional capacity impairments (post-MI and non-post-MI) can be distinguished.     

Cardiogenic shock: single center experience with and without on-site catheterization facilities

BACKGROUND: The beneficial effect of on-site catheterization facilities on the survival of all patients with myocardial infarction complicated by cardiogenic shock has been questioned. Our objective was to evaluate the impact of the availability of on-site catheterization facilities on the outcome of unselected patients with cardiogenic shock. METHODS AND RESULTS: We studied the hospital records of 70 consecutive patients with cardiogenic shock admitted to our intensive coronary care unit during 1990-1996, and compared two groups of patients: those admitted before (n = 34) and after (n = 36) the opening of our catheterization laboratory. Patients admitted when the catheterization laboratory was available were of similar age, but included fewer males and fewer patients with prior myocardial infarction. Following the activation of the catheterization laboratory, utilization rates of coronary angiography, percutaneous transluminal coronary angioplasty and intra-aortic balloon pump increased, compared with the previous period. However, there was no improvement in in-hospital (88 vs. 83%; p = 0.7) and 30-day mortality (91 vs. 86%; p = 0.7) before versus after the activation of our catheterization laboratory. Twelve patients selected to cardiac catheterization (9 underwent percutaneous transluminal coronary angioplasty) experienced lower in-hospital and 30-day mortality compared with patients who were not selected (58 vs. 96, and 67 vs. 96%, respectively; p < 0.02). CONCLUSIONS: Following the activation of the catheterization laboratory, the mortality of the entire population of cardiogenic shock patients remained relatively unchanged. Still, a small subgroup of these patients selected for urgent cardiac catheterization had a lower mortality compared with patients who were not selected.