[Cardiovascular manifestations in patients with COPD]

Cardiac autonomic function in patients with acute exacerbation of chronic obstructive pulmonary disease with and without ventricular tachycardia

Background

Autonomic dysfunction in patients with chronic obstructive pulmonary disease (COPD) may increase the risks of arrhythmia and sudden death. We studied cardiac autonomic function in patients with acute exacerbation of COPD (AECOPD).

Methods

Patients with AECOPD were classified into ventricular tachycardia (VT) and non-VT groups according to the presence or absence of VT. The following parameters derived from 24-h Holter monitoring were compared between groups: average heart rate, heart rate deceleration capacity (DC), heart rate acceleration capacity (AC), standard deviation of normal RR intervals (SDNN), standard deviation of average RR interval in 5-min segments (SDANN), root mean square of standard deviations of differences between adjacent normal RR intervals (rMSSD), low-frequency power (LF), high-frequency power (HF) and LF/HF ratio.

Results

Seventy patients were included, 22 in the VT group and 48 in the non-VT group. The groups had similar clinical characteristics (except for more common amiodarone use in the VT group, P < 0.05) and general ECG characteristics. DC, SDNN, SDANN and rMSSD were lower and AC higher in the VT group (P < 0.05). In the VT group, DC was correlated positively with SDNN (r = 0.716), SDANN (r = 0.595), rMSSD (r = 0.571) and HF (r = 0.486), and negatively with LF (r = -0.518) and LF/HF (r = -0.458) (P < 0.05). AC was correlated negatively with SDNN (r = -0.682), SDANN (r = -0.567) and rMSSD (r = -0.548) (P < 0.05).

Conclusions

DC decreased and AC increased in patients with AECOPD and VT, reflecting an imbalance in autonomic regulation of the heart that might increase the risk of sudden death.

Do preoperative pulmonary function indices predict morbidity after coronary artery bypass surgery?

Context:

The reported prevalence of chronic obstructive pulmonary disease (COPD) varies among different groups of cardiac surgical patients. Moreover, the prognostic value of preoperative COPD in outcome prediction is controversial.

Aims:

The present study assessed the morbidity in the different levels of COPD severity and the role of pulmonary function indices in predicting morbidity in patients undergoing coronary artery bypass graft (CABG).

Settings and Design:

Patients who were candidates for isolated CABG with cardiopulmonary bypass who were recruited for Tehran Heart Center-Coronary Outcome Measurement Study.

Methods:

Based on spirometry findings, diagnosis of COPD was considered based on Global Initiative for Chronic Obstructive Lung Disease category as forced expiratory volume in 1 s [FEV1]/forced vital capacity <0.7 (absolute value, not the percentage of the predicted). Society of Thoracic Surgeons (STS) definition was used for determining COPD severity and the patients were divided into three groups: Control group (FEV1 >75% predicted), mild (FEV1 60–75% predicted), moderate (FEV1 50–59% predicted), severe (FEV1<50% predicted). The preoperative pulmonary function indices were assessed as predictors, and postoperative morbidity was considered the surgical outcome.

Results:

This study included 566 consecutive patients. Patients with and without COPD were similar regarding baseline characteristics and clinical data. Hypertension, recent myocardial infarction, and low ejection fraction were higher in patients with different degrees of COPD than the control group while male gender was more frequent in control patients than the others. Restrictive lung disease and current cigarette smoking did not have any significant impact on postoperative complications. We found a borderline P = 0.057 with respect to respiratory failure among different patients of COPD severity so that 14.1% patients in control group, 23.5% in mild, 23.4% in moderate, and 21.9% in severe COPD categories developed respiratory failure after CABG surgery.

Conclusion:

Among post-CABG complications, patients with different levels of COPD based on STS definition, more frequently developed respiratory failure. This finding may imply the prognostic value of preoperative pulmonary function test for determining COPD severity and postoperative morbidities.

[Comorbidities in COPD: a new challenge in clinical practice]

Today it is a recognised fact that chronic obstructive pulmonary disease (COPD) is a real systemic disease that is respiratory-based. Recently, the focus has been on the importance of the comorbidities that are associated with COPD, such as all the cardiovascular diseases, lung cancer, diabetes, metabolic syndrome, peripheral muscular dysfunction, depression, anxiety, osteoporosis and anaemia, etc. These comorbidities constitute a new medical and therapeutic challenge with regard to COPD; their high frequency and considerable impact on the quality of life and the prognosis for survival of the patients make them a key element. The aims of this focus are to present the spectrum and prevalence of comorbidities in COPD, to obtain an objective view as to why and how these comorbidities should be systematically assessed and treated in patients, and subsequently to discuss the impact of this new data in clinical practice and in research. This recent data is another positive step in understanding the disease, optimising the diagnosis, and assessing and caring for COPD patients.