Clinical significance of changes in β-adrenoreceptors in peripheral lymphocytes in patients with essential hypertension

Objective To explore the relationship of β-adrenoreceptor density and function with the condition of patients with essential hypertension.Methods In the present study, 69 male patients with essential hypertension at different stages were compared with a group of age-matched normotensive controls. β-ad renoreceptor maximum bound volume (B(max)) in peripheral lymphocytes was mea sured by (3)H-dihydroalprenolol ((3)H-DHA) radio ligand binding. β- adrenoreceptor responsiveness was determined by Salbutamol (injection). Results In patients with essential hypertension at stages Ⅰ and Ⅱ, B(max) was si gnificantly higher (P<0.01 and P<0.001, respectively) and the chronot ropic doses of Salbutamol required to increase the heart rate by 30 beats/min (CD(30)) were significantly lower (P<0.01 and P<0.001, respect ively) than in age-matched normotensive control subjects. In patients with ess ential hypertension at stage Ⅲ, B(max) was significantly lower and CD(30)was significantly higher (both P<0.01) than those in the age-matched n ormotensive control subjects. B(max) was significantly higher and CD(30) was significantly lower (both P<0.001) in patients with essential hyper tensi on and with left ventricular hypertrophy (LVH) than that in patients with essent ial hypertension but without LVH. In patients with essential hypertension and heart failure, B(max) was significantly lower and CD(30) was significant ly higher (both P<0.001) than those in patients with essential hypertension without heart failure.Conclusions The changes of β-adrenoreceptor density and function were related to hypertens ion, hypertension complicated with ventricular hypertrophy, and heart failure. They may be viewed as indexes of the condition in the patients with essential hy pertension.     

Short-term effect of cardiac resynchronization therapy in patients with ischaemic or nonischaemic cardiomyopathy

Background Patients with heart failure were candidates for cardiac resynchronization therapy （CRT） regardless of underlying aetiology. This study observed the effect of CRT in patients with ischaemic or nonischaemic cardiomyopathy. Methods One hundred and forty-two patients with refractory chronic heart failure and left bundle branch block received cardiac resynchronization therapy, 91 men and 51 women, average age 60 years. Left ventricular ejection fraction （LVEF） was severely depressed （mean 29%）, left ventricular end diastolic diameter （LVEDD） enlarged （mean 72 mm） and QRS width was lengthened （mean 147 ms）. Ninety-eight had nonischaemic cardiomyopathy and 44 had ischaemic cardiomyopathy. Results After cardiac resynchronization therapy, the heart function was significantly improved. The mean LVEF increased from 29% to 36% after pacing. In patients with nonischaemic cardiomyopathy, the LVEF was improved from 28% to 37%, and in patients with ischaemic cardiomyopathy, the LVEF was improved from 30% to 36%. No significant difference of the improvement was found between the two groups （P〉0.05）. Conclusions Cardiac resynchronization therapy could significantly improve cardiac function in patients with chronic heart failure regardless of the underlying heart disease.     

Evaluation of left ventricular rotation and twist using speckle tracking imaging in patients with atrial septal defect

Speckle tracking imaging （STI） was employed to investigate the effect of right ventricular （RV） volume and pressure overload on left ventricular （LV） rotation and twist in 35 patients with atrial septal defect （ASD）, 18 of which with pulmonary hypertension, and 21 healthy subjects serving as controls. The peak rotations of 6 segments at the basal and apical short-axises and the average peak rotation and interval time of the 6 segments in the opposite direction during early systolic phase were measured respectively. LV twist versus time profile was drawn and the peak twist and time to peak twist were calculated. LV ejection fraction （EF） was measured by Biplane Simpson. Compared to ASD patients without pulmonary hypertension and healthy subjects, the peak rotations of posterior, inferior and postsept walls at the basal level were lower （P〈0.05）, and the average counterclockwise peak rotation of 6 segments at the basal level during early systolic phase was higher （P〈0.05）, and the average interval time was delayed （P〈0.05）. LV peak twist was also lower （P〈0.05）, and had a significant negative correlation with pulmonary arterial systolic pressure （r=-0.57, P=0.001）. No significant differences were found in LVEF among the three groups. It was suggested that although RV volume overload due to ASD has no significant effects on LV rotation and twist, LV peak twist is lower in ASD patients with pulmonary hypertension. Thus LV twist may serve as a new indicator of the presence of pulmonary hypertension in ASD patients.     

Primary prevention of sudden cardiac death by implantable cardioverter-defibrillator therapy in Chinese patients with heart failure: a single-center experience

Background An implantable cardioverter-defibrillator （ICD） has been suggested for heart failure patients for primary prevention of sudden cardiac death. However, few data have been reported on the application of ICD as primary prevention of sudden cardiac death in China. We evaluated the value of primary prevention ICD therapy in Chinese patients with heart failure.Methods Thirty-four patients at an average age of （60.2±13.7） years seen in Peking Union Medical College Hospital were treated with ICD implantation for primary prevention of sudden cardiac death from November 2005 to July 2009. Single-chamber ICDs were implanted in 16 （47.0%） cases, and dual-chamber or cardiac resynchronization therapy defibrillators in 18 （53.0%） cases. The patients had an average left ventricular ejection fraction of （26.9±5.5）% （11% to 35%）, of which 18 （53.0%） patients had ischemic cardiomyopathy and 16 （47.0%） patients had non-ischemic cardiomyopathy. All patients were followed up at three months after the implantation and every six months thereafter or when prompted by an ICD event.Results There were five （14.7%） deaths, including two of heart failure and three with a non-cardiac course, during an average follow-up of （15.0±11.9） months. Forty-one ICD therapy events were recorded, including 19 （46.3%） appropriate ICD therapies in six patients and 22 （53.7%） inappropriate ICD therapies in four patients with single chamber leads. Inappropriate ICD therapies were mainly due to supraventricular tachyarrhythmias, especially atrial fibrillation. Patients with ischemic cardiomyopathy and non-ischemic cardiomyopathy did not differ in the incidence of either appropriate or inappropriate therapy.Conclusions ICD for primary prevention of sudden cardiac death in China prevents patients from arrhythmia death. Relatively high incidence of inappropriate therapies highlights the importance of an atrial lead.     

Relationship between Ambient Fine Particles and Ventricular Repolarization Changes and Heart Rate Variability of Elderly People with Heart Disease in Beijing,China

Objective To explore the effects of particulate matters less than 2.5 μm in aerodynamic diameter (PM 2.5) on heart repolarization/depolarization and heart rate variability (HRV). Methods We conducted a panel study for elderly subjects with heart disease in Beijing from 2007 to 2008. PM 2.5 was measured at a fixed station for 20 h continuously each day while electrocardiogram (ECG) indexes of 42 subjects were also recorded repeatedly. Meteorological data was obtained from the China Meteorological Data Sharing Service System. A mixed linear regression model was used to estimate the associations between PM 2.5 and the ECG indexes. The model was adjusted for age, body mass index, sex, day of the week andmeteorology. Results Significant adverse effects of PM 2.5 on ECG indexes reflecting HRV were observed statistically and the strongest effect of PM 2.5 on HRV was on lag 1 day in our study. However, there were no associations between PM 2.5 and ECG indexes reflecting heart repolarization/depolarization. Additionally, the effects of PM 2.5 on subjects with hypertension were larger than on the subjects without hypertension. Conclusion This study showed ambient PM 2.5 could affect cardiac autonomic function of the elderly people with heart disease, and subjects with hypertension appeared to be more susceptive to the autonomic dysfunction induced by PM 2.5.     

Embolic events in 93 elderly Chinese patients with atrial fibrillation

Objectives To evaluate the prevalence of embolic events and relevant factors in elderly Chinese patients with atrial fibrillation(AF), and to provide evidence on ways to prevent embolic events.Methods Autopsy data from ninety-three continous elderly Chinese patients with AF were analysed. The incidence of embolic events and its relationship to underlying disease, pathologic changes in the heart, and other clinical characteristics were examined.Results Embolism were observed in 27 of 93 cases, with an incidence of 29.03%. The incidence of embolic events was higher in elderly patients with rheumatic heart disease than those with coronary artery disease, hypertensive myocardiopathy and heart diseases. Patients with chronic AF,with a course of AF≥3 years, and those with heart failure or diabetes had a higher incidence of embolic events than those without these complications. There was significant difference in incidence between paroxysmal and chronic AF. Patients with left atrial or ventricular enlargement, mural thrombosis in cardiac chambers, valvular calcification and valvular vegetation also had a higher incidence of embolic events. Oral dipyridamole (75-150 mg/d) or aspirin (50-150 mg/d) showed no definite effects in preventing embolism in some patients.Conclusions There was a high incidence of embolic events in elderly Chinese patients with AF. Anticoagulation therapy should be provided to the elderly patients with AF, especially to the patients with risk factors for embolism.     

Complications of cardiac resynchronization therapy in patients with congestive heart failure

Background Previous clinical studies have suggested that patients with congestive heart failure and intraventricular conduction delay could benefit from cardiac resynchronization therapy （CRT）. Implantation of left ventricular lead is a complex procedure with some potential for complications. This study was conducted to analyse the complications of CRT in patients with congestive heart failure. Methods Totally 117 patients, 86 males and 31 females, mean age of 53 years, with congestive heart failure and intraventricular conduction delaywere enrolled in this study. Venography was performed on all patients. Different types of coronary sinus leads were used to pace the left ventricle. Results Left ventricular lead was attempted to implant through coronary sinus for all the 117 patients and was successfully implanted in 111 patients. The success rate was 94.9%. Main complications rate was 6.8%, including coronary sinus dissection in 4 patients, phrenic nerve stimulation required lead repositioning in 2 patients and lead dislodgement in 2 patients. Conclusions It is feasible and safe to pace left ventricle through coronary sinus. However, there are some procedural complications.     

Surgical intervention for advanced valvular heart disease in 227 cases

Background Although the results of surgical treatment in cardiac valve disease continue to improve, the postoperative mortality rate and the rate of complications in patients with advanced valvular heart disease (AVHD) are still very high. We did this retrospective study to summarize the surgical experience of heart valve replacement for patients with AVHD and discuss effective ways to improve the surgical outcome.Methods From January 1994 to October 2003, surgical procedures of heart valve replacement were performed on 227 (136 men and 91 women) patients with AVHD in our Department of Cardiothoracic Surgery. The clinical data of all patients were collected and analysed. Patients’ age ranged from 10 years to 77 years. In preoperative cardiac function grading, 157 cases were NYHA III and 70 cases NYHA IV. Fifty-one patients had had cardiac operations. The ultrasonic cardiac graphs showed that 145 patients suffered from moderate or severe pulmonary hypertension and 73 had combined giant left ventricle. Mitral valve replacement was performed in 32 cases, aortic valve replacement in 90, tricuspid valve replacement in 1, combined mitral and aortic replacement in 103 and combined mitral and tricuspid replacement in 1. Nineteen patients also received surgical corrections for other minor abnormalities during the operations. A logistic model was established to evaluate the influence of perioperative factors on the mortality rate. Results The operative mortality rate was 13.2% (30/227). The main causes of death included multiple organ dysfunction syndrome (MODS), low cardiac output syndrome and ventricular fibrillation. From the results of the binary noncounterpart multivariate logistic regression, the following statistically significant factors were found to influence the operative mortality rate: redo operation, age ≥55 years, preoperative NYHA cardiac function grading, extracorporeal circulation time ≥120 minutes and postoperative usage of GIK (glucose, insulin and potassium) solution. All factors were risk ones except postoperative application of GIK. The Hosmer-Lemeshow goodness of fit coefficient of this model was 0.976. Conclusions The risk factors associated with postoperative mortality rate in the patients with AVHD were redo operation, age ≥55 years, preoperative NYHA cardiac function grading and extracorporeal circulation time ≥120 minutes. Postoperative usage of GIK acted as a kind of metabolic therapy and will improve the recovery for patients with AVHD. Active perioperative management and care will play a very important role in reducing the operative risk and improving the short term outcome of surgical treatment for the patients with AVHD.     

Troponin not just a simple cardiac marker: prognostic significance of cardiac troponin

Objective The object of this study was to review the role of cardiac troponin as a prognostic factor in acute coronary syndrome patients of varying circumstances. Data sources The data used in this review were obtained mainly from the studies of cardiac troponin reported in pubmed from 1981 to 2006. Study selection Relevant articles on studies of cardiac troponin were selected. Results Elevated cardiac troponin in patients with ST elevation and non ST elevation myocardial infarction was associated with adverse outcomes, including a higher incidence of congestive heart failure, shock, and death. Patients with elevated cardiac troponin value seemed to benefit more from invasive strategies including a percutaneous coronary intervention and bypass surgery, but elevated cardiac troponin was also correlated with adverse outcomes, including a higher degree of failure, shock, and mortality in patients undergoing percutaneous coronary intervention; a higher degree of perioperative myocardial infarction, low cardiac output syndrome, cardiopulmonary resuscitation, and new-onset ventricular arrhythmia in patients undergoing bypass surgery were also observed. Elevated troponin after a percutaneous coronary intervention seemed to be associated with short-term adverse outcomes rather than long-term adverse outcomes, unless the elevation of the troponin post percutaneous coronary intervention was quite high （about 5 times above normal）. On the contrary, elevated cardiac troponin after bypass surgery was more confusing to analyze since it happened in almost all patients. Furthermore, differences in cutoff values and time measurements in some studies add more confusion; thus, further research is warranted. Conclusions The prognostic value of cardiac troponin is demonstrated in almost all acute coronary syndrome patients. In addition to its high sensitivity and specificity, the prognostic value of cardiac troponin is another reason to make it the ＂golden cardiac marker＂ of this time.     

Effect of atrial pacing therapy with selective pacing algorithms on paroxysmal atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia among the elderly. Its incidence increases dramatically with increasing age and decreasing left ventricular function, peaking in subjects with overt congestive heart failure.1 Because of the unsatisfactory efficacy and possible serious side effects of clinically available anti-AF drugs for AF patients with sick sinus syndrome, pacing techniques have recently been applied in the treatment of AF. The cardiac pacemaker Vitatron Selection 900E has special AF diagnostic and prophylactic therapy algorithms. The objective of this study was to use the diagnostic information concerning the onset mechanisms of AF to program the preventive pacing algorithms for each patient individually and to find out whether a reduction in AF burden could be achieved.     

New approach for new target: adaptive servo-ventilation on Cheyne-Stokes respiration in congestive heart failure

Cheyne-Stokes respiration with central sleep apnea （CSR-CSA） occurs when periods of hyperventilation with waxing/waning tidal volume alternated with periods of central hypopnea/apnea. It is present in approximately 40 percent of patients with severe congestive heart failure （CHF）. CSR-CSA may contribute to the progression of heart failure by causing repetitive arterial oxygen desaturation, sleep fragmentation, increased left ventricular afterload, activation of sympathetic nervous system, and oscillations in heart rate and blood pressure. There are evidences indicating that CSR-CSA is associated with a remarkable increase in mortality and is also an independent risk factor for cardiac transplantation; furthermore, treatment of CSR-CSA in combination with optimal medical therapy may influence the course of chronic heart failure, improve quality of life and the survival of patients. The paper by Zhang et al^2 highlights the importance of recognizing this pathological breathing pattern as a potential therapeutic target.     

THE EFFECTS OF MANIFEST AND LATENT PROPAGATED SENSATION ALONG THE CHANNEL ON THE ACUPUNCTURE REGULATION OF CARDIAC FUNCTION

The influence of propagated sensation along thechannel (PSC) on the effect of acupuncture atNeiguan (P6) acupoint was investigated in 170subjects.All the eight parameters of cardiac functionsproduced marked changes in 76 cases with PSC andto a lesser degree in 94 cases with no manifest PSC.There were significant differences in seven parametersbetween the two groups.Of the 94 subjects with no manifest PSC,58(62%) showed latent PSC.After stimulation on theNeiguan point,seven parameters were changed signi-ficantly in the subjects with positive latent PSC,while six parameters were not changed in subjectswith no latent PSC.There were obvious differencesin six parameters between the two groups.The results indicated that acupuncture onNeiguan Improved the cardiac function and ECGvery remarkably in subjects with manifest PSCtoward the heart and also in subjects with positivelatent PSC.Both manifest and latent PSC hadobvious regulative effects on the solid and holloworgans belonging to this meridian,though to a diffe-rent degree.     

Symptomatic hemodynamic and hormonal effects of intravenous captopril in patients with heart failure.

Since only oral preparations of captopril are clinically available, intravenous captopril was studied in 10 patients with mild heart failure and in 20 severe. The results showed that intravenous captopril may rapidly reduce cardiac preload and afterload, increase cardiac output, inhibit reninangiotensin-aldosterone system, and depress plasma levels of catecholamine. After captopril infusion, a rapid symptomatie improvement occurred and the infusion could be well tolerated in patients with acute or severe heart failure. In addition, reversing hyponatremia and hypokalemia or improving azotcmia may benefit the patients with acute or severe heart failure.     

Assessment of Left Ventricular Global Twist in Essential Hypertensive Heart by Speckle Tracking Imaging

The left ventricular twist was evaluated by 2-dimensional ultrasound speckle-tracking imaging （STI） in 50 patients with hypertension with normal geometric left ventricle （LV） and 45 normal subjects as control group. The mean value of LV rotation was obtained at each plane Using STI. LV twist and twist velocity were defined as apical rotation/rotation rate relative to the base respectively. To adjust the intersubject differences in heart rates, the time sequence were normalized. The results showed that peak twist developed near the end of systole. Peak LV twist was significantly higher in patients with hypertension than normal controls （P〈0.001）. The diastolic untwisting mainly occurred in early diastole （=38%）. Compared with normal controls, untwisting rate （Untw R） in patients with hypertension was significantly reduced （P〈0.001）, and untwisting half-time （UHT） was significantly delayed （P〈0.05）. This study demonstrated that STI has a potential ability to evaluate the early change of heart function in patients with hypertension by measuring the twist of LV.     

Optimized cardiac resynchronization therapy in patients with congestive heart failure

Heart failure was a major and increasing public health problem, with an almost ＂epidemic＂ increase in the number of patients. Despite recent advances in pharmacotherapy, the prognosis remains poor. Cardiac resynchronization therapy （CRT）, by pacing right and left ventricles, has been proved to improve symptoms and reduce mortality for heart failure patients with cardiac dyssynchrony, However, 20% to 30% of patients did not respond to CRT. The good cardiac synchronicity before CRT and the remaining atrioventficular, inter- and intra-ventricular dyssynchrony after CRT may explain the non-response. New echocardiographic techniques, and in particular tissue Doppler imaging （TDI） analysis, has been proved to be a helpful tool in evaluating cardiac dyssynchrony, as well as in assessing the degree of cardiac resynchronization after biventricular device implantation. So, in this study, we optimized the pacing parameters to determine whether echo-guided optimizing of AV/VV delays would enhance the effect of CRT on cardiac function and synchronicity.     

Effects of Yixin Jiangya Capsules on Insulin Resistance and Tumor Necrosis Factor-α in Cases of Primary Hypertension with Left Ventricular Hypertrophy

Objectives: To observe the effects of Yixin Jiangya Capsules (益心降压胶囊 capsules for nourishing the heart and lowering blood pressure) on insulin resistance (IR) and tumor necrosis factor-α (TNF-α) in patients with primary hypertension with left ventricular hypertrophy (LVH). Methods: Totally 93 cases were randomly divided into a control group of 31 cases taking Enalapril and a treatment group of 62 cases taking Enalapril and Yixin Jiangya Capsules. Results: Fasting serum insulin (FSI) and TNF-α obviously increased and insulin sensitive index (ISI) significantly decreased in both groups before treatment as compared to those of a healthy group. After treatment, FSI, TNF-α and fasting blood glucose (FBG) obviously decreased and ISI remarkably increased in the treatment group, while ISI significantly increased and TNF-α obviously decreased in the control group. The curative effect in the treatment group was remarkably superior to that in the control group. FSI was positively related to TNF-α before treatment in both groups. Conclusion: FSI and TNF-α obviously increase and ISI significantly decreases in patients with primary hypertension with LVH. FSI and TNF-α influencing each other are involved in the generation and development of hypertension. Yixin Jiangya Capsules can improve IR and decrease TNF-α.     

Cardiac resynchronization therapy and B-type natriuretic peptide in heart failure

Cardiac resynchronization therapy （CRT） improves left ventricular function, symptom status, quality of life and reduces hospitalization and mortality in patients with New York Heart Association （NYHA） Class Ⅲ or Ⅳ heart failure and intraventricular conduction delay despite optimal medical management. B-type natriuretic peptide （BNP） and its amino terminal cleavage equivalent （NT-pro BNP） levels correlate with the severity of heart failure and predict prognosis of heart failure patients. In this issue of the journal, the study reported by Ding et al found that percentage change in NT-pro BNP levels from baseline to 3 months was a strong predictor for long-term response to CRT. These investigators studied 44 patients with NYHA class Ⅲ or Ⅳ heart failure and wide QRS （〉120 ms）.     

QT Dispersion Level and Its Clinical Significance.in Dilated Cardiomyopathy

Objective To evaluate the clinical significance of QT dis persion (QTd, QTcd) in dilated cardiomyopathy (DCM). Methods QTd and QTcd were measured on simultaneously recording 12-lead electrocardiograms ( ECGs) in 60 DCM patients and cormpared with 60 healthy subjects. Results The values of QTd and QTcd in DCM were significantly higher than those in control group ( P ＜ 0. 01 ). With subgroup analysis, QTd and QTcd in patients uith cardiac sudden death (CSD) were longer than those in survivors and those died of progressive heart failure ( P ＜ 0. 05), patients with ventricular tachycardia (VT) or with severe heart failure than those without (compared uith patients with ventricular premature beats [V PB], P＜0.05, compared with patients without ventricular arrhythmia [VA], P＜0. 01) or with mild heart failure (P＜0. 01). The values of QTd and QTcd in patients with VPB were greater than those in patients without VA( P＜ 0. 05). There were significant differences in the rates of VT, CSD and heart failure between the groups of QTd＞ 110 ms and QTd≤110 ms(P＜0. 01 or P＜0.05), in contrast to ejection fraction (EF) and fractional shortening (FS)( P＞0.05). Conclusion The values of QTd and QTcd increased in DCM patients were susceptive index for monitoring maligant VA in DCM, also important prognostic markers of CSD. QTd was correlated with NY HA functional class but not with EF and FS.     

PDK1 plays a critical role in regulating cardiac function in mice and human

Background PDK1 is an essential protein kinase that plays a critical role in mammalian development. Mouse lacking PDK1 leads to multiple abnormalities and embryonic lethality at E9.5. To elucidate the role of PDK1 in the heart, we investigated the cardiac phenotype of mice that lack PDK1 in the heart in different growth periods and the alteration of PDK1 signaling in human failing heart.Methods We employed Cre/loxP system to generate PDK1flox/flox： α-MHC-Cre mice, which specifically deleted PDK1 in cardiac muscle at birth, and tamoxifen-inducible heart-specific PDK1 knockout mice （PDK1flox/flox：MerCreMer mice）, in which PDK1 was deleted in myocardium in response to the treatment with tamoxifen. Transmural myocardial tissues from human failing hearts and normal hearts were sampled from the left ventricular apex to analyze the activity of PDK1/Akt signaling pathways by Western blotting.Results PDK1flox/flox： α-MHC-Cre mice died of heart failure at 5 and 10 weeks old. PDK1flox/flox-MerCreMer mice died of heart failure from 5 to 21 weeks after the initiation of tamoxifen treatment at 8 weeks old. We found that expression levels of PDK1 in human failing heart tissues were significantly decreased compared with control hearts.Conclusion Our results suggest that PDK1 signaling network takes part in regulating cardiac viability and function in mice, and may be also involved in human heart failure disease.     

Attenuation of myocardial apoptosis by alpha-lipoic acid through suppression of mitochondrial oxidative stress to reduce diabetic cardiomyopathy

Background Cardiac failure is a leading cause of the mortality of diabetic patients. In part this is due to a specific cardiomyopathy, referred to as diabetic cardiomyopathy. Oxidative stress is widely considered to be one of the major factors underlying the pathogenesis of the disease. This study aimed to test whether the antioxidant α-lipoic acid （α-LA） could attenuate mitochondrion-dependent myocardial apoptosis through suppression of mitochondrial oxidative stress to reduce diabetic cardiomyopathy. Methods A rat model of diabetes was induced by a single tail intravenous injection of streptozotocin （STZ） 45 mg/kg. Experimental animals were randomly assigned to 3 groups： normal control （NC）, diabetes （DM） and DM treated with α-LA （α-LA）. The latter group was administered with a-LA （100 mg/kg ip per day）, the remainder received the same volume vehicle. At weeks 4, 8, and 12 after the onset of diabetes, cardiac apoptosis was examined by TUNEL assay. Cardiomyopathy was evaluated by assessment of cardiac structure and function. Oxidative damage was evaluated by the content of malondialdehyde （MDA）, reduced glutathione （GSH） and the activity of manganese superoxide diamutase （Mn-SOD） in the myocardial mitochondria. Expression of caspase-9 and caspase-3 proteins was determined by immunohistochemistry and mitochondrial cytochrome c release was detected by Western blotting Results At 4, 8, and 12 weeks after the onset of diabetes, significant reductions in TUNEL-positive cells, caspase-9,-3 expression, and mitochondrial cytochrome c release were observed in the α-LA group compared to the DM group. In the DM group, the content of MDA in the myocardial mitochondria was significantly increased, and there was a decrease in both the mitochondrial GSH content and the activities of Mn-SOD. They were significantly improved by α-LA treatment. HE staining displayed structural abnormalities in diabetic hearts, while α-LA reversed this structural derangement. The index of cardiac function （±dp/dtmax） in the diabetes group was aggravated progressively from 4 weeks to 12 weeks, but α-LA delayed deterioration of cardiac function （P 〈0.05）. Conclusions Our findings indicate that the antioxidant α-LA can effectively attenuate mitochondria-dependent cardiac apoptosis and exert a protective role against the development of diabetic cardiomyopathy. The ability of α-LA to suppress mitochondrial oxidative damage is concomitant with an enhancement of Mn-SOD activity and an increase in the GSH content of myocardial mitochondria.