Prognostic Significance of Frontal QRS-T Angle in Patients with Idiopathic Dilated Cardiomyopathy

Background： Current risk stratification of idiopathic dilated cardiomyopathy （IDC） lacks sufficient sensitivity and specificity. The objective of this study was to investigate the predictive role of frontal QRS-T angles in IDC. Methods： A prospective study with 509 IDC patients was performed from February 2008 to December 2013 in the Affiliated Drum Tower Hospital, Nanjing University School of Medicine. Baseline values and changes in QRS-T angles were recorded. Follow-up was conducted every 6 months. Analyses by Cox Proportional Hazards model were performed to evaluate the association between QRS-T angle and outcomes. The primary outcome of interest was all-cause mortality. Results： During a median follow-up of 34 months, 90 of 316 patients with QRS-T angles 〉90° died compared to 31 of 193 patients with QRS-T angles ≤90° （hazard ratio [HR] 2.4, P 〈 0.001）. Cardiac death was more prevalent in patients with a wide QRS-T angle （HR 2.4, P 〈 0.001）, similar to heart failure rehospitalization （HR = 2.5, P 〈 0.001）. After adjustment for potential prognostic factors, the QRS-T angle was independently associated with all-cause mortality （HR - 2.5, P 〈 0.05）, cardiac mortality （HR = 1.9, P 〈 0. 05）, and heart failure rehospitalization （HR = 2.3, P 〈 0.01）. Optimized therapy significantly narrowed the frontal QRS-T angle （100.9 ±53.4° vs. 107.2 ± 54.4°, P 〈 0.001 ）. The frontal QRS-T angle correlated well with established risk factors, such as left ventricular ejection fraction, brain natriuretic peptide, and New York Heart Association functional class. Conclusions; The frontal QRS-T angle is a powerful predictor of all-cause mortality, cardiac mortality, and worsening heart failure in IDC patients, independent of well-established prognostic factors. Optimized therapy significantly narrows the QRS-T angle, which might be an indicator of medication compliance, but this requires further investigation.

Electrocardiographic alterations in patients with chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease(COPD)have an increased risk for cardiovascular events,and electrocardiography has an important role in detecting cardiac side effects of COPD-related hypoxia.

Correlation between Age and Electrical Axes of the Heart in Adult Nigerians

Background: P wave axis, QRS axis, T wave axis and QRS-T angle have prognostic values on cardiovascular morbidity and mortality, yet the effect of age on these important electrocardiographic parameters has not been well studied in adult Nigerians, knowing that some electrocardiographic parameters are affected by age. Objectives: This study was aimed at determining the effect of age on P frontal axis, QRS frontal axis, T frontal axis and frontal QRS-T angle among adult Nigerians. Methods: This was a retrospective study in which P frontal axis, QRS frontal axis and T frontal axis of adult patients who attended a university teaching hospital were determined from 12-lead ECG. Frontal QRS-T angle was calculated as the absolute difference between the QRS frontal axis and T wave frontal axis. The electrical axes and QRS-T angle were correlated with age. Results: There were 85 cases aged between 20 and 66 years, which included 42 males and 43 females. P frontal axis correlated positively and non-significantly with age (r = -0.032, p = 0.773), QRS frontal axis correlated negatively and significantly with age (r = -0.295, p = 0.006), T frontal axis correlated negatively and non-significantly with age (r = -0.002, p = 0.984), while frontal QRS-T angle correlated negatively and significantly with age (r = -0.266, p = 0.014). Conclusion: There were significant age related changes in both QRS frontal axis and frontal QRS-T angle. No significant age related changes were found in P frontal axis and T frontal axis.