Assessment of left ventricular systolic synchrony and cardiac function in patients with ischemic heart disease by echocardiography

OBJECTIVE

To investigate the correlation between left ventricular systolic synchrony and cardiac function in patients with ischemic heart diseases of different degrees by echocardiography.

PATIENTS AND METHODS

84 cases of patients with ischemic heart diseases were consecutively selected including 28 cases of asymptomatic heart failure, 40 cases of mild to moderate heart failure, and 16 cases of severe and refractory heart failure. Interventricular synchrony was evaluated by echocardiography, and the result was expressed by interventricular mechanical delay (IVMD). The ventricular systolic synchrony was evaluated by the standard deviation of systole tmax (Ts-SD), cardiac function indexes included left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter (LVEDd), and BNP and QRS wave duration.

RESULTS

IVMD, Ts-SD and QRS wave duration increased gradually following the exacerbation of heart failure; differences were statistically significant (p < 0.05). The ratio of the QRS wave duration that was equal to or greater than 120 ms among three groups showed no statistical difference (p = 0.593). In patients with QRS wave durations equal to or greater than 120 ms compared to patients with durations less than 120 ms, the levels of IVDM, Ts-SD, LVEDd, and serum BNP were increased (p < 0.05) while levels of LVEF were decreased (p < 0.05). There were no significant linear correlations among values of IVMD, Ts-SD with LVEF, LVEDd, BNP and QRS wave duration (p > 0.05).

CONCLUSIONS

Left ventricular systole synchrony was different in patients with different degrees of ischemic heart diseases, and a comprehensive assessment of the combination of ventricular systole synchrony with cardiac function is needed.

Correlation between blood asymmetric dimethylarginine level and the complications of patients with cardiovascular diseases

This study aimed to investigate the correlation between blood asymmetric dimethylarginine (ADMA) and the complications of patients with cardiovascular diseases through studying the level changes of ADMA, endothelial nitric oxide synthase (eNOS) and NO. Two hundred research subjects with small differences in gender ratio and age, including 50 patients with hypertension combined with myocardial infarction, 50 patients with hypertension, 50 patients with myocardial infarction and 50 healthy normal controls, were enrolled. Relevant basic indexes were measured and recorded; the blood ADMA levels of all the research subjects were detected using high pressure liquid chromatography (HPLC) within the required time. Furthermore, the levels of eNOS and NO were detected using enzyme-linked immunosorbent assay and the relevant information, such as blood pressure, was recorded. The comparison and analysis results of data obtained through detection demonstrated that the subjects in the four groups were well comparable. It was found that the myocardial infarction combined with hypertension group had a much higher serum ADMA level and relatively low levels of eNOS and NO compared to those of the other three groups; the myocardial infarction group and the hypertension group had a much higher serum ADMA level compared to that of the healthy control group and the two groups had much lower levels of eNOS and NO. Moreover, the serum ADMA level was in a positive correlation with the severity of cardiovascular diseases and it showed a significant difference in patients with different severity of hypertension. The change of blood ADMA level can induce acute myocardial infarction as well as the occurrence of cardiovascular disease-associated complications.

Clinical significance and levels of blood brain natriuretic peptides in patients with persistent atrial fibrillation before and after catheter ablation

The aim of this study was to observe levels of blood brain natriuretic peptides (BNPs) in patients with persistent atrial fibril-lation (AF) before and after catheter ablation. Thirty-six patients with persistent AF (28 successful surgeries and eight recurrent cases) and 36 healthy controls with normal sinus rhythm were recruited for this study. BNP levels in the AF and control groups were measured before and after catheter ablation. BNP levels before surgery were significantly higher in the persistent AF group than in the control group (P < 0.01). The successful surgery group had distinctly lower BNP levels before ablation than the recurrent group (P < 0.01). In the recurrent group, BNP levels 2 h after ablation were significantly lower than those be-fore ablation (P < 0.01); these levels increased after AF recurrence (P < 0.01) and were comparable with those before ablation (P < 0.01). Logistic regression analysis indicated that the BNP level was an inde-pendent factor for and predictor of AF recurrence (P < 0.01). The BNP level in patients with persistent AF is clinically important in predicting and evaluating AF recurrence after ablation.

Effect of prolonged dual anti-platelet therapy on reducing myocardial infarction rate after percutaneous coronary intervention

This paper aimed to review the interferential effect of prolonged dual anti-platelet therapy after Percutaneous Coronary Intervention (PCI), and the influence on reducing the myocardial infarction rate. A computer search was carried out in the relevant libraries and databases, regarding all the short-term (≤ 6 months) and long-term (> 6 months) dual anti-platelet therapies, and the curative and observational studies on the effects and safety of interventional therapy. RevMan5.1 software was used to meta-analyze the standard research. A total of 8 papers were finally selected. In the randomized controlled research, meta-analysis showed that the myocardial infarction rate of a long-term dual antiplatelet treatment group was lower than the short-term treatment group [OR=0.74, 95% CI (0.56, 0.98), P < 0.0001]. The meta-analysis of observational research showed that the myocardial infarction rate of the long-term treatment group was lower than the short-term treatment group [OR=0.7, 95% CI (0.45, 1.08), P=0.11]; the incidence rate of late stent thrombosis in the long-term treatment group was lower than in the short-term treatment group [OR=0.40, 95% CI (0.15, 1.07), P=0.07]. It can be concluded that in the long-term group (>6 months) dual anti-platelet therapy after PCI can reduce the incidence rate of myocardial infarction or death. In addition, long-term treatment can reduce the occurrence tendency of late stent thrombosis. Furthermore, in the long-term treatment group, serious bleeding events did not increase.

Safety and efficacy of intracoronary tirofiban administration in patients with serious thrombus burden and ST-elevation myocardial infarction undergoing percutaneous coronary intervention

OBJECTIVE

This work aims to explore the safety and efficacy of intracoronary tirofiban administration in patients with serious thrombus burden and ST-elevation myocardial infarction (STEMI) undergoing emergency percutaneous coronary intervention (PCI).

PATIENTS AND METHODS

A total of 104 patients with serious thrombus burden and acute STEMI were randomly divided into treatment (intracoronary tirofiban administration, 56 cases) and control (48 cases) groups. Comparison of coronary blood flow, ST-segment resolution (STR), duration of hospital stay, 30-day major adverse cardiac events (MACE) and complications such as hemorrhage was conducted.

RESULTS

In treatment group, the percentage of thrombolysis in myocardial infarction-3 (TIMI-3) flow in the infarct-related artery (IRA) increased (89.3% to 85.4, p < 0.05), blood flow in the IRA calculated with TIMI frame count method enhanced [(1.68 ± 0.23) ml/s to (1.42 ± 0.31) ml/s, p < 0.05], STR on electrocardiogram (ECG) enlarged [(64.3 ± 7.84)% to (48.6 ± 6.47)%, p < 0.05)] and the prevalence of MACE decreased (10.7% to 18.8%, p < 0.05), all of which were significantly different from those of control group, but no statistical difference in complications was observed between two groups (p > 0.05).

CONCLUSIONS

It was simple, safe and effective to perform intracoronary tirofiban administration in patients with serious thrombus burden and STEMI when undergoing emergency PCI.

Regulatory functions of docosahexaenoic acid on ion channels in rat ventricular myocytes

OBJECTIVE

The aim of this study was to study the regulatory functions of docosahexaenoic acid (DHA) on resting potential (RP), action potential duration (APD), delayed rectifier potassium current (Ik), and inwardly rectifier potassium current (Ik1) in rat ventricular myocytes, and analyze the related anti-arrhythmia mechanism.

MATERIALS AND METHODS

Rat ventricular myocytes were isolated by enzyme digestion method. RP, APD, Ik and Ik1 in individual ventricular myocytes were recorded by patch-clamp technique with whole-cell configuration. Effects of DHA with various concentrations (0, 20, 40, 60, 80, 100 and 120 mmol/L, respectively) on RP, AP, Ik and Ik1 were investigated.

RESULTS

There was no statistical difference of RP with different DHA concentrations (p > 0.05, n = 20), and the 25%, 50% and 90% of APD (APD25, APD50, and APD90) were gradually prolonged with increase of DHA concentration, respectively (p < 0.05, n = 20). IK gradually blocked and the I-V curve was downward shifted, according to increase of DHA concentration (p < 0.05, n = 20). The DHA half effect concentration (EC50) was 47.52 ± 2.32 µmol/L. With increasing DHA concentration, the steady-state inactivation curve shifted to left, and the recovery curve shifted to right. DHA had no significant effect on IK1 (p > 0.05, n = 20).

CONCLUSIONS

DHA has regulatory functions on RP, APD, Ik and Ik1 in rat ventricular myocytes, which may be one of the related antiarrhythmic mechanisms.