Effect of Exercise-Based Cardiac Rehabilitation Following Coronary Artery Bypass Surgery on Ventricular Repolarization Indices

Barriers and Facilitators to Delivering Inpatient Cardiac Rehabilitation: A Scoping Review

Objective

The purpose of this scoping review was to summarize the literature on barriers and facilitators that influence the provision and uptake of inpatient cardiac rehabilitation (ICR).

Methods

A literature search was conducted using PsycINFO, MEDLINE, EMBASE, CINAHL and AgeLine. Studies were included if they were published in English after the year 2000 and focused on adults who were receiving some form of ICR (eg, exercise counselling and training, education for heart-healthy living). For studies meeting inclusion criteria, descriptive data on authors, year, study design, and intervention type were extracted.

Results

The literature search resulted in a total of 44,331 publications, of which 229 studies met inclusion criteria. ICR programs vary drastically and often focus on promoting physical exercises and patient education. Barriers and facilitators were categorized through patient, provider and system level factors. Individual characteristics and provider knowledge and efficacy were categorized as both barriers and facilitators to ICR delivery and uptake. Team functioning, lack of resources, program coordination, and inconsistencies in evaluation acted as key barriers to ICR delivery and uptake. Key facilitators that influence ICR implementation and engagement include accreditation and professional associations and patient and family-centred practices.

Conclusion

ICR programs can be highly effective at improving health outcomes for those living with CVDs. Our review identified several patient, provider, and system-level considerations that act as barriers and facilitators to ICR delivery and uptake. Future research should explore how to encourage health promotion knowledge amongst ICR staff and patients.

Impact of cardiac rehabilitation on ventricular repolarization indices following coronary artery bypass grafting

Background

The aim of this study was to evaluate the effect of cardiac rehabilitation on electrocardiographic changes in patients undergoing isolated coronary artery bypass grafting.

Methods

Between January 2016 and July 2019, a total of 625 patients (485 males, 140 females; mean age: 59.6 years; range, 50.6 to 68.6 years) who underwent isolated coronary artery bypass grafting and survived were retrospectively analyzed. The patients were divided into two groups according to the participation in the cardiac rehabilitation program as follows: the Rehab(+) group (n=363) and the Rehab(-) group (n=262). Electrocardiographic parameters of both groups were compared.

Results

There was a significant decrease in the electrocardiographic findings of heart rate (p<0.001), QTc (p<0.001), Tpe duration (p<0.001), Tpe/QT ratio (p<0.001), and Tpe/QTc ratio (p<0.001) in the Rehab(+) group before and after surgery. There was a significant decrease in the Rehab(+) group, compared to the Rehab(-) group, in terms of parameters of QT interval (p=0.001), QTc (p=0.017), Tpe duration (p<0.001), Tpe/QT ratio (p<0.001), and Tpe/QTc ratio (p<0.001).

Conclusion

Cardiac rehabilitation program after coronary artery bypass grafting decreases ventricular repolarization indices of electrocardiography. Based on these changes, postoperative cardiac rehabilitation program may reduce the risk of ventricular arrhythmia and sudden cardiac death during follow-up.

Long-term high-intensity interval training associated with lifestyle modifications improves QT dispersion parameters in metabolic syndrome patients

BACKGROUND

QT dispersion (QTd) is a marker of myocardial electrical instability, and is increased in metabolic syndrome (MetS). Moderate intensity continuous exercise (MICE) training was shown to improve QTd in MetS patients.

OBJECTIVES

To describe long-term effects of MICE and high-intensity interval exercise training (HIIT) on QTd parameters in MetS.

METHODS

Sixty-five MetS patients (53 ± 9 years) were assigned to either a MICE (60% of peak power output [PPO]), or a HIIT program (alternating phases of 15-30 s at 80% of PPO interspersed by passive recovery phases of equal duration), twice weekly during 9 months. Ventricular repolarization indices (QT dispersion=QTd, standard deviation of QT = sdQT, relative dispersion of QT = rdQT, QT corrected dispersion = QTcd), metabolic, anthropometric and exercise parameters were measured before and after the intervention.

RESULTS

No adverse events were noted during exercise. QTd decreased significantly in both groups (51 vs 56 ms in MICE, P < 0.05; 34 vs 38 ms in HIIT, P < 0.05). Changes in QTd were correlated with changes in maximal heart rate (r = -0.69, P < 0.0001) and in heart rate recovery (r = -0.49, P < 0.01) in the HIIT group only. When compared to MICE, HIIT training induced a greater decrease in weight, BMI and waist circumference. Exercise capacity significantly improved by 0.82 and 1.25 METs in MICE and HIIT groups respectively (P < 0.0001). Lipid parameters also improved to the same degree in both groups.

CONCLUSION

In MetS, long-term HIIT and MICE training led to comparable effects on ventricular repolarization indices, and HIIT might be associated with greater improvements in certain cardiometabolic risk factors.