Experimental & Clinical Cardiology最新文献

Objectives: At present, there are conflicting data on the ability of echocardiographic parameters to predict the exercise-induced elevation of left ventricular (LV) filling pressure. The purpose of the present study was to validate the ratio of early diastolic transmitral (E) to mitral annular velocity (e') obtained at peak exercise in its capacity to determine the exercise-induced elevation of pulmonary capillary wedge pressure (PCWP) and to reveal new noninvasive parameters with such capacity.

Methods: Sixty-one patients who had undergone heart transplantation with normal LV ejection fraction underwent simultaneous exercise echocardiography and right heart catheterization.

Results: In 50 patients with a normal PCWP at rest, exercise E/e' ≥8.5 predicted exercise PCWP ≥25 mmHg with a sensitivity of 64.3% and a specificity of 84.2% (area under the curve [AUC]=0.74). A comparable or slightly better prediction was achieved by exercise E/peak systolic mitral annular velocity (s') ≥11.0 (sensitivity 79.3%; specificity 57.9%; AUC=0.75) and exercise E/LV systolic longitudinal strain rate ≤-105 cm (sensitivity 78.9%; specificity 78.6%; AUC=0.87). Combined, exercise E/s' and exercise E/e' resulted in a trend toward a slightly more precise prediction (sensitivity 53.6%; specificity 89.5%; AUC=0.78) than did either variable alone.

Conclusions: Exercise E/e', used as a sole parameter, is not sufficiently precise to predict the exercise-induced elevation of PCWP. Exercise E/s', E/LV systolic longitudinal strain rate or combinations of these parameters may represent further promising possibilities for predicting exercise PCWP elevation.

Angina is a clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back or arm. It is typically aggravated by exertion or emotional stress and relieved by nitroglycerin. Atherosclerotic coronary artery disease is the most common cause of angina. Dual-chamber pacemakers track the atrial electrical activity by pacing the ventricle. The present article reports the first case in the literature involving pacemaker-mediated angina. A 78-year-old man complained of chest pain shortly after the placement of a permanent dual-chamber pacemaker and experienced immediate relief of his pain after the pacemaker mode was switched from tracking the atrium and pacing the ventricle to sensing and pacing the ventricle. The pain was identified as angina pectoris. The comprehensive history-taking performed before pacemaker placement helped to quickly identify the cause of the patient's pain.

Background: Diabetes is a major risk factor for heart failure (HF), although the pathophysiological processes have not been clarified.

Objective: To determine the prevalence of HF and of abnormal myocardial perfusion in diabetic patients evaluated using technetium (99m) sestamibi single-photon emission computed tomography.

Methods: An observational cross-sectional study was conducted that included patients with type 2 diabetes mellitus who underwent echocardiography to diagnose HF and a pharmacological stress test with intravenous dipyridamole to examine cardiac scintigraphic perfusion abnormalities. Clinical and biochemical data were also collected.

Results: Of the 160 diabetic patients included, 92 (57.6%) were in HF and 68 (42.5%) were not. When patients were stratified according to the presence of abnormal myocardial perfusion, those with abnormal perfusion had a higher prevalence of HF (93%) than those with normal perfusion (44.4%) (P<0.0001). Patients with HF weighed more (P=0.03), used insulin less frequently (P=0.01), had lower total cholesterol (P=0.05) and high-density lipoprotein cholesterol concentrations (P=0.002), and a greater number of their myocardial segments showed abnormal perfusion (P≤0.001). More HF patients had a history of myocardial infarction (P<0.001) compared with those without HF. In a logistic regression analysis, the number of segments exhibiting abnormal myocardial perfusion was an independent risk factor for HF.

Conclusions: The prevalence of HF in diabetic patients was high and HF predominantly occured in association with myocardial ischemia.

Objective: To evaluate left ventricular (LV) systolic asynchrony and its relationship with the Tei index using tissue Doppler imaging (TDI); and to evaluate the relationship of thrombolysis in myocardial infarction frame count (TFC) and Tei index with LV asynchrony in patients with coronary artery ectasia (CAE).

Methods: A total of 50 CAE patients and 40 control subjects were evaluated. Diagnosis of CAE was made angiographically and TFC was calculated. LV systolic and diastolic function was assessed by conventional echocardiography and TDI. Evaluation of intra-LV systolic asynchrony was performed using tissue synchronization imaging (TSI).

Results: In patients with CAE, the Tei index was significantly higher than in controls (0.63±0.12 versus 0.52±0.12; P<0.001). LV systolic asynchrony parameters of TSI including SD of the peak tissue velocity (Ts) of the 12 LV segments (Ts-SD-12), maximal difference in Ts between any two of the 12 LV segments (Ts-12), SD of the Ts of the six basal LV segments (Ts-SD-6), maximal difference in Ts between any of the six basal LV segments (Ts-6) were significantly lengthened in patients with subclinical hypothyroidism compared with controls (P<0.001, P<0.001, P<0.001 and P<0.001, respectively). In addition, a positive correlation was found between Ts-SD-12 and the Tei index in patients with CAE (r=0.841; P<0.001) and mean TFC was positively correlated with Ts-SD-12 and the Tei index (r=0.345; P=0.013 and r=0.291; P=0.021, respectively).

Conclusion: Patients with CAE exhibit evidence of LV systolic asynchrony according to TSI. LV systolic asynchrony is related to the Tei index and mean TFC. Furthermore, the Tei index is an independent risk factor for LV systolic asynchrony.

Background: Aortic dilation may critically precede progression to thoracic aortic aneurysm (TAA). Prolonged or repetitive isometric-type heavier strenuous activities resulting from the nature of some professions may be an important causative factor for TAA.

Method: The echocardiographic measurement data of middle-age subjects who were isometric-type daily strenuous activity trainers or ordinary activity trainers were retrospectively analyzed. Clinical features and echocardiographic parameters of the left ventricle and left atrium (LA), aortic root (AR) and ascending aorta (AA) were compared between the groups.

Results: AR (35.6±3.0 mm versus 33.5±1.9 mm), AA (36.8±3.0 mm versus 34.4±1.9 mm) and LA (37.4±2.2 mm versus 36.2±2.2 mm) diameters were significantly enlarged in the strenuous activity trainer group versus the ordinary activity group. Diastolic blood pressure was significantly lower (73.8±5.9 mmHg versus 78.3±6.0 mmHg) in this group. AR diameter was correlated with height (β=0.460; P=0.004) and LA diameter (β=0.280; P=0.008) while AA diameter was correlated with type of profession (β=0.309; P=0.003), left ventricular systolic diameter (β=0.500; P=0.001) and LA diameter (β=0.272; P=0.005) in regression analysis.

Conclusion: Aortic dilation and, subsequently, TAA may be an occupational disease due to nature of some professions (eg, the military, security, weight lifters, athletes, heavy workers, etc). Echocardiography is a convenient method of imaging that could be easily applied either during preparticipation screening or during periodical examination of these subjects. Earlier detection of TAA and limitation of such strenuous activities in these individuals may be initial lifesaving measures for the prevention of future cases of aortic aneurysm and dissection.

Objective: To investigate the feasibility and safety of using sheathless standard guiding catheters for transradial percutaneous coronary intervention (PCI) to treat bifurcation lesions.

Methods: Coronary bifurcation lesions were identified using angiography in 43 patients with coronary artery disease. These patients underwent transradial PCI using sheathless standard guiding catheters, and the procedural success and complication rates were recorded.

Results: All 43 patients underwent successful PCI. The Culotte stenting technique was used in 22 (51.2%) subjects, the Crush stenting technique was used in eight (18.8%) subjects and the crossover stenting implantation technique was used in 13 (30.0%) subjects. Of the 43 coronary artery bifurcation lesions, the final kissing balloon technique was performed in 39 (90.1%) lesions. Adjunctive devices used in the cohort included intravascular ultrasound for 32 (74.4%) patients, thrombus aspiration catheters for two patients and cutting balloon for five patients. During the perioperative period, no major complications associated with vessel puncture or adverse cardiac or cerebrovascular events occurred in any of the 43 patients enrolled in the present study. At day 30, radial artery occlusion was detected in only three (2.5%) patients and radial artery stenosis in four (9.3%) patients. At six-month follow-up, 24 (55.8%) patients exhibited coronary artery patency with no significant intimal hyperplasia.

Conclusions: Transradial PCI using the sheathless technique may be a feasible and safe technique to treat coronary bifurcation lesions.

Background: Although seasonal variation in hospitalizations due to chronic heart failure is recognized, the possible contributors to such variability are less well documented.

Methods: Records from all admissions to 12 hospitals in Hubei province, China, over a 10-year period with diagnostic codes for chronic systolic heart failure (CSHF) were reviewed. A total of 16,145 patients with CSHF were analyzed.

Results: There was a marked seasonal variation in the number of hospitalizations due to CSHF, with two peaks in the monthly rate of hospitalization due to CSHF occurring in December and August compared with the spring and autumn months. Monthly hospitalizations due to CSHF for patients with New York Heart Association class III and IV ranged from a peak of 40.4% and 23.3% above average in December and August, respectively, to 18.6% below average in November, while hospitalizations due to CSHF for patients with New York Heart Association class I and II exhibited no obvious seasonal variation. Blood sodium level (95% CI 2.132 to 2.144; P=0.036) was an independent risk factor for hospitalizations due to CSHF in August.

Conclusion: The number of hospitalizations due to CSHF increased during the colder and warmer months in China. A low blood sodium level was associated with the peak in hospitalizations in August.

Omega-3 polyunsaturated fatty acids (PUFA) confer protection against myocardial injury after ischemia-reperfusion. There are two subfractions of mitochondria located in different regions of the cell: subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM). The present study explored possible differences between Ca(2+)-induced mitochondrial swelling in rat SSM and IFM fractions under control conditions (control group [CG]) and after dietary supplementation with omega-3 PUFA (experimental group [EG]). Changes in mitochondrial matrix volumes were measured using the light-scattering technique. In the CG, the time courses of swelling were comparable in both mitochondrial fractions, with no difference in Ca(2+)-induced swelling between the two mitochondrial fractions. In the SSM fraction, no difference in the time course of swelling in Ca(2+)-free solution between CG and EG was detected. In the EG, both SSM and IFM fractions demonstrated a decreased sensitivity to Ca(2+); IFM fractions, however, exhibited significantly less pronounced swelling following Ca(2+) addition. The authors conclude that IFM and SSM fractions do not differ in their sensitivity to Ca(2+)-induced swelling. While dietary omega-3 PUFA protected both mitochondrial fractions against Ca(2+)-evoked swelling, the protective effect appeared to be more pronounced for the IFM fraction than for the SSM fraction.