Phasic Compression of Left Circumflex Coronary Artery during Atrial Systole.

Phasic coronary artery compression is typically associated with spasm or myocardial bridging. Compression caused by acquired anatomic changes to the surrounding heart chambers has been reported only infrequently. We present a possibly unique case of phasic compression of the proximal left circumflex coronary artery during atrial contraction in association with a dilated left atrium. A 55-year-old man with multiple cardiac risk factors presented with worsening exertional dyspnea. An electrocardiogram and echocardiogram revealed marked left atrial dilation and a left ventricular ejection fraction of 0.15 to 0.20 with elevated filling pressures. Angiograms showed compression of the proximal segment of the left circumflex coronary artery during late ventricular diastole: the compression occurred in phase with atrial systole, whereas good flow without compression was present during atrial diastole. We attributed this phenomenon to ballooning of the lateral region of the atrial wall toward the atrioventricular groove during atrial systole. The patient complied with antihypertensive therapy, and his status improved after one year. To identify coronary artery compression in the presence of abnormal chamber geometry and to guide the treatment of the contributing medical conditions, we recommend careful analysis of angiographic results.

Regular treadmill exercise inhibits mitochondrial accumulation of cholesterol and oxysterols during myocardial ischemia-reperfusion in wild-type and ob/ob mice.

Mitochondria play a central role in the irreversible damages induced to the heart by a prolonged period of ischemia followed by reperfusion. We previously demonstrated that (1) myocardial ischemia-reperfusion induces mitochondrial accumulation of cholesterol and oxysterols that are deleterious for the organelle; (2) inhibition of cholesterol and oxysterol accumulation prevents mitochondrial injury at reperfusion; (3) exercise is cardioprotective and remains efficient in the presence of co-morbidities such as obesity. The aim of this study was to investigate whether regular exercise limits mitochondrial cholesterol and oxysterol accumulation in wild-type and obese mice. Wild-type C57BL/6J and obese (ob/ob) mice were assigned to sedentary conditions or regular treadmill exercise and submitted to 30min of coronary artery occlusion followed by 15min of reperfusion. Regular exercise improved oxidative phosphorylation, restored the antioxidant capacity of the heart by increasing the expression of SOD1 and catalase and reduced the mitochondrial generation of oxysterols in wild-type as well as in ob/ob mice. In wild-type animals, exercise limited the production of oxysterols. In ob/ob mice, despite hypercholesterolemia, chronic exercise abolished the mitochondrial accumulation of cholesterol and concomitantly reduced the generation of 7α-hydroxycholesterol, 7-ketocholesterol and cholesterol-5α,6α-epoxide. In conclusion, regular exercise prevents the mitochondrial accumulation of cholesterol and oxysterols which occurs during early reperfusion of an ischemic myocardium in mice. This effect is observed in normo and hypercholesterolemic animals. It may be partly responsible for the antioxidant properties of regular exercise and contribute to its cardioprotective effect in obese conditions.

Impact of exercise-based cardiac rehabilitation on long-term clinical outcomes in patients with left main coronary artery stenosis.

BACKGROUND: Cardiac rehabilitation may reduce cardiovascular mortality and morbidity rates in patients with coronary artery disease. The specific relationship between cardiac rehabilitation participation and left main coronary artery stenosis is unknown. DESIGN: Prospective registry analysis. METHODS: Data from a registry of 3120 patients with left main coronary artery stenosis, collected between 1995 and 2010, were analyzed. A total of 596 patients (19.6%) had participated in a cardiac rehabilitation program. RESULTS: The crude seven-year mortality, cardiovascular mortality, target-vessel revascularization and myocardial infarction rates were significantly lower in the cardiac rehabilitation than in the non-rehabilitation group, and the incidence of stroke tended to be lower in the cardiac rehabilitation group. Multivariate analysis showed that cardiac rehabilitation was associated with significantly lower risks of mortality (hazard ratio (HR), 0.70; 95% confidence interval (CI), 0.49-1.00; p = 0.05) and cardiovascular mortality (HR, 0.69; 95% CI, 0.48-0.97; p = 0.03). However, the adjusted HR of myocardial infarction, target-vessel revascularization and stroke did not differ significantly. Propensity score-matched analysis of 507 pairs showed that cardiac rehabilitation was associated with significant decreases in mortality (HR, 0.62; 95% CI, 0.43-0.89; p = 0.009) and cardiovascular mortality (HR, 0.54; 95% CI, 0.36-0.80; p = 0.002) but had no beneficial effects on myocardial infarction, target-vessel revascularization or stroke. CONCLUSIONS: Exercise-based cardiac rehabilitation participation was associated with significant decreases in mortality. Our findings show that cardiac rehabilitation programs should be implemented in standard management for patients with left main coronary artery stenosis.

Effect of exercise-based cardiac rehabilitation on non-culprit mild coronary plaques in the culprit coronary artery of patients with acute coronary syndrome.

Approximately, 70 % of acute myocardial infarctions are known to develop from mild atherosclerotic lesions. Therefore, it is important to evaluate mild coronary plaques to prevent acute coronary syndrome (ACS). The aim of the present study was to investigate the effects of exercise-based cardiac rehabilitation (CR) on mild coronary atherosclerosis in non-culprit lesions in patients with ACS. Forty-one men with ACS who underwent emergency percutaneous coronary interventions and completed a 6-month follow-up were divided into CR and non-CR groups. Quantitative coronary angiography (QCA) was performed using the automatic edge detection program. The target lesion was a mild stenotic segment (10-50 % stenosis) at the distal site of the culprit lesion, and the segment to be analyzed was determined at a segment length ranging from 10 to 15 mm. The plaque area was significantly decreased in the CR group after 6 months, but was significantly increased in the non-CR group (P < 0.05). The low-density lipoprotein (LDL) cholesterol, LDL/high-density lipoprotein (HDL) ratio and high-sensitivity C-reactive protein (Hs-CRP) levels were significantly reduced in both groups (P < 0.01). Peak VO2 in the CR group was significantly increased (P < 0.01). Changes in the plaque area correlated with those in Hs-CRP in both groups, while that association with those in HDL-C was observed in only CR group. Stepwise regression analysis revealed the decrease in Hs-CRP as an independent predictor of plaque area regression in the CR group. CR prevented the progression of mild coronary atherosclerosis in patients with ACS.

[Public access defibrillation: successful cardiopulmonary resuscitation due to automatic external defibrillator at traffic accident]. / Public-Access-Defibrillation: erfolgreiche Reanimation durch Einsatz eines automatischen externen Defibrillators nach Verkehrsunfall.

HISTORY: A 65-year-old man collapsed after he stepped out of his car after a traffic accident. TREATMENT: Fortunately, two police officers on a routine patrol in the area were quickly on the scene and started cardiopulmonary resuscitation. A passerby noticed that the patient was in distress and that an automatic defibrillator was nearby. He attached the electrodes of the defibrillator to the chest of the patient in accordance with instructions on the defibrillator and terminated the ventricular fibrillation (200 joule, biphasic). COURSE: Emergency cardiac catheterization revealed a subtotal stenosis proximally in the right coronary artery, which was successfully treated with a stent. Based on the ideal basic life support, the immediate care by emergency mobile system and coronary angioplasty with successful revascularisation the patient could be released without any neurological deficit. CONCLUSION: This case illustrates that laypersons can use automatic external defibrillator in case of cardiac resuscitation sufficiently and quickly.

Beneficial effects of cardiac rehabilitation in patients with incomplete revascularization after primary coronary angioplasty.

BACKGROUND: There are no reliable data concerning the safety and benefits of physical rehabilitation in patients with a two-vessel disease before the second stage of angioplasty. The aim of this study was to evaluate the efficiency of early cardiac rehabilitation in patients with acute coronary syndromes and with angiographically significant residual coronary artery stenosis after a successful percutaneous coronary intervention (PCI) into the culprit lesion. DESIGN: Retrospective analysis of the results of coronary angiograms and exercise tests of patients who underwent stationary rehabilitation after their first ACS and first PCI. SETTING: Cardiac Rehabilitation Department. POPULATION: One hundred ninety patients divided into 2 groups according to the completeness of myocardial revascularization; 49 with significant (≥70%) coronary artery stenosis in a non-culprit vessel, the mean diameter reduction 80±9%; and 141 without any residual stenosis. The prevalence of classical risk factors was comparable in both groups. Rehabilitation was conducted as a stationary 3-week program. METHODS: Comparison of the initial and final exercise test workload in both groups, as well as the frequency of adverse effects during the program. RESULTS: Physical training in patients with incomplete revascularization (IR) was safe and well tolerated. Significant increase of workload capacity after the rehabilitation program was observed in both groups: in the IR group from 7.3±3.0 to 8.8±2.9 MET (P<0.0001) and in the complete revascularization (CR) group - from 7.6±2.8 to 9.2±2.9 MET (P<0.0001). No significant difference was observed in initial workload capacities (P=0.9813) nor in final workload capacities (P=0.8571) between the two groups. Two patients in the group with residual lesion (4%) and one in the group without residual lesion (0.7%) required urgent PCI during the rehabilitation program, P=0.1637. CONCLUSION: Early postinfarction physical training is safe and efficient for patients after complete revascularization and for those with untreated non-culprit coronary artery stenosis. Gradual increase in physical training intensity under cardiologist supervision is essential in identifying those rare patients for whom the second stage of angioplasty should not be delayed. CLINICAL REHABILITATION IMPACT: Our study shows that patients with incomplete revascularization may be qualified for cardiac rehabilitation programs.

Exercise and diet-induced weight loss attenuates oxidative stress related-coronary vasoconstriction in obese adolescents.

Obesity is a disease of oxidative stress (OS). Acute hyperoxia (breathing 100 % O(2)) can evoke coronary vasoconstriction by the oxidative quenching of nitric oxide (NO). To examine if weight loss would alter the hyperoxia-related coronary constriction seen in obese adolescents, we measured the coronary blood flow velocity (CBV) response to hyperoxia using transthoracic Doppler echocardiography before and after a 4-week diet and exercise regimen in 6 obese male adolescents (age 13-17 years, BMI 36.5 ± 2.3 kg/m(2)). Six controls of similar age and BMI were also studied. The intervention group lost 9 ± 1 % body weight, which was associated with a reduced resting heart rate (HR), reduced diastolic blood pressure (BP), and reduced RPP (all P < 0.05). Before weight loss, hyperoxia reduced CBV by 33 ± 3 %. After weight loss, CBV only fell by 15 ± 3 % (P < 0.05). In the control group, CBV responses to hyperoxia were unchanged during the two trials. Thus weight loss: (1) reduces HR, BP, and RPP; and (2) attenuates the OS-related coronary constrictor response seen in obese adolescents. We postulate that: (1) the high RPP before weight loss led to higher myocardial O(2) consumption, higher coronary flow and greater NO production, and in turn a large constrictor response to hyperoxia; and (2) weight loss decreased myocardial oxygen demand and NO levels. Under these circumstances, hyperoxia-induced vasoconstriction was attenuated.

Relation of body mass index to fatal and nonfatal cardiovascular events after cardiac rehabilitation.

The aim of the present study was to determine whether body mass index (BMI) influences survival and recurrent cardiovascular events in a cardiac rehabilitation population. We followed 389 consecutive entrants to cardiac rehabilitation for 6.4 +/- 1.8 years. Patients were stratified into 3 groups: normal (BMI 18 to 24.9 kg/m(2)), overweight (BMI 25 to 29.9 kg/m(2)), and obese (BMI > or =30 kg/m(2)). Total and cardiovascular mortality were inversely associated with BMI category in bivariate models. However, only cardiovascular mortality was significant after adjustment for age and gender (p < 0.044), with cardiovascular death rates of 10% in normal, 8% in overweight, and 2% in obese patients. The rates of nonfatal recurrent events were 10% in normal, 24% in overweight, and 25% in obese patients. Our data indicate that BMI is inversely related to cardiovascular mortality but positively related to the risk of nonfatal recurrent events.

Effects of phase I cardiac rehabilitation on anxiety of patients hospitalized for coronary artery bypass graft in Taiwan.

OBJECTIVE: To assess the effects of phase I cardiac rehabilitation intervention on anxiety of patients hospitalized for coronary artery bypass graft (CABG) surgery. DESIGN: Prospective, quasi-experimental, random assignment, repeated measurements. SETTING: The Veterans General Hospital Taipei, Taiwan, Republic of China. PATIENTS: Seventy patients were randomly assigned to (1) the phase I cardiac rehabilitation intervention (experimental) group and (2) the nonintervention (comparison) group. Ultimately, 60 subjects were included in the data analyses. OUTCOME MEASURES: Psychological status was evaluated by the state of anxiety scores on the State-Trait Anxiety Inventory. Anxiety scores were measured 3 times: (1) after admission, before the patient underwent CABG surgery; (2) the day before the patient underwent CABG surgery; and (3) the day of discharge from the hospital. INTERVENTION: Individual instruction in progressive exercises and daily activities according to the phase I cardiac rehabilitation program (Chinese manual) were used during hospitalization. RESULTS: Data analysis was performed with use of generalized estimating equations (GEE) to assess the between- and within-group variations. The mean anxiety for all subjects before undergoing CABG surgery was 42.6. The mean anxiety on the day before undergoing CABG surgery was 33.7 in the experimental group and 49.8 in the comparison group; there were statistical differences, with a P <.05 level of significance between these 2 groups. The mean anxiety on the day of discharge in the experimental group was 28.6 and in the comparison group was 38.4; there were statistical differences, with a P <.05 level of significance between these 2 groups. CONCLUSIONS: These results have been supported by similar studies. This finding suggests that application of phase I cardiac rehabilitation intervention can reduce the anxiety level during hospitalization of patients undergoing CABG surgery.

Low dose dobutamine echocardiography for predicting functional recovery after coronary revascularisation.

OBJECTIVE: To evaluate the effects of chronic coronary occlusion on the accuracy of low dose dobutamine echocardiography in predicting recovery of dysfunctional myocardium after revascularisation. DESIGN: Retrospective study. SETTING: Tertiary referral centre. PATIENTS: 53 consecutive patients with >/= 70% stenosis of the left anterior descending coronary artery (LAD) and regional ventricular dysfunction (group 1, non-occluded LAD; group 2, occluded LAD) who underwent dobutamine echocardiography. INTERVENTIONS: 26 patients underwent coronary artery bypass grafting and 27 had percutaneous transluminal coronary angioplasty. MAIN OUTCOME MEASURES: Baseline studies before revascularisation included cross sectional echocardiography at rest and during dobutamine infusion (5-10 microgram), and coronary angiography. The dobutamine study was performed mean (SD) 35 (28) days before revascularisation. Echocardiography at rest was repeated 90 (48) days after revascularisation. RESULTS: Of 296 dysfunctional segments, 63 in group 1 (43%; 63/146) and 69 in group 2 (46%; 69/150) (NS) improved at follow up. Mean (SD) regional wall motion score index decreased from 1.97 (0.48) (95% confidence interval (CI) 1.01 to 2.93) before revascularisation to 1.74 (0.52) (95% CI 0.70 to 2.78) at follow up in group 1 (p = 0.001), and from 2.12 (0.41) (95% CI 1.30 to 2.98) to 1.88 (0.36) (95% CI 1.16 to 2.60) in group 2 (p = 0.0006). In group 1, sensitivity (87% v 52%; p < 0.0001), negative predictive value (88% v 65%; p = 0.001), and accuracy (77% v 64%; p = 0.01) were all significantly higher than in group 2, despite the angiographic evidence of collaterals in patients with occluded vessels. CONCLUSIONS: Dobutamine echocardiography shows reduced sensitivity in predicting recovery of dysfunctional myocardium supplied by totally occluded vessels. Thus caution should be used in selecting such patients for revascularisation on the basis of a viability assessment made in this way.