Prolonged PR interval, or first degree AV block, has been traditionally regarded as a benign electrocardiographic finding in healthy individuals, until recent studies have suggested that it may be ...associated with increased mortality and morbidity. The aim of this study was to further elucidate clinical and prognostic importance of prolonged PR interval in a large middle-aged population with a long follow-up.
We evaluated 12-lead electrocardiograms of 10 785 individuals aged 30-59 years (mean age 44 years, 52% males) recorded between 1966 and 1972, and followed the subjects for 30 ± 11 years. Prolonged PR interval was defined as PR >200 ms, with further analysis performed using PR ≥220 ms. Main endpoints were all-cause mortality, cardiovascular mortality, and sudden cardiac death, and other endpoints included hospitalizations due to cardiovascular causes. During the baseline examination, prolonged PR interval >200 ms was present in 2.1% of the subjects, but PR interval normalized to ≤200 ms in 30% of these individuals during the follow-up. No increase in mortality or in hospitalizations due to coronary artery disease, heart failure, atrial fibrillation, or stroke was associated with prolonged PR interval (P = non-significant for all endpoints). These results were not changed after multivariate adjustment or in several subanalyses.
In the middle-aged general population, prolonged PR interval normalizes in a substantial proportion of subjects during the time course, and it is not associated with an increased risk of all-cause or cardiovascular mortality.
Short-QT syndrome is an inherited disorder characterized by a short QT interval and an increased risk of sudden cardiac death. The clinical significance of a short QT interval observed in a randomly ...recorded ECG is not known. Therefore, we assessed the prevalence and prognostic significance of a short QT interval in a general population.
QT intervals were measured from the 12-lead ECGs of 10 822 randomly selected middle-aged subjects (5658 males, mean age 44+/-8.4 years) enrolled in a population study and followed up for 29+/-10 years. The end points were all-cause and cardiovascular mortality. In addition to Bazett's method (corrected QT interval, or QTc), the Fridericia (QTfc) and nomogram (QTnc) methods were used to correct the QT interval for heart rate. The cutoff values for short QT intervals were defined as 320 ms (very short) and 340 ms (short). The prevalence of QT interval <320 ms based on QTc, QTfc, and QTnc was 0.10%, 0.08%, and 0.06%, and the prevalence of QT interval <340 ms was 0.4%, 0.3%, and 0.3%, respectively. The majority of subjects with short QT intervals were males. All-cause or cardiovascular mortality did not differ between subjects with a very short or short QT interval and those with normal QT intervals (360 to 450 ms). There were no sudden cardiac deaths, aborted sudden cardiac deaths, or documented ventricular tachyarrhythmias among subjects with a QTfc <340 ms.
A short QT interval does not appear to indicate an increased risk for all-cause or cardiovascular mortality in middle-aged nonreferral, community-based individuals.
Clinical presentation, occurrence of sudden infant death, and results of the available therapies in the largest group of patients with short QT syndrome (SQTS), studied so far, are reported.
Clinical ...history, physical examination, electrocardiogram (ECG), exercise stress testing, electrophysiological study, morphological evaluation, genetic analysis and therapy results in 29 patients with SQTS and personal and/or familial history of cardiac arrest are reported. The median age at diagnosis was 30 years (range 4-80). In all subjects, structural heart disease was excluded. Eighteen patients were symptomatic (62%): 10 had cardiac arrest (34%) and in 8 (28%) this was the first clinical presentation. Cardiac arrest had occurred in the first months of life in two patients. Seven patients had syncope (24%); 9 (31%) had palpitations with atrial fibrillation documented even in young subjects. At ECG, patients exhibited a QT interval < or = 320 ms and QTc < or = 340 ms. Fourteen patients received an implantable cardioverter-defibrillator (ICD) and 10 hydroquinidine prophylaxis. At a median follow-up of 23 months (range 9-49), one patient received an appropriate shock from the ICD; no patient on hydroquinidine had sudden death or syncope.
SQTS carries a high risk of sudden death and may be a cause of death in early infancy. ICD is the first choice therapy; hydroquinidine may be proposed in children and in the patients who refuse the implant.
The variations in the electrocardiographic patterns of J-point elevations, and the complex of J-points and J-waves in early repolarization (ER), in conjunction with disparities in associated sudden ...cardiac death (SCD) risk, have lead to a recognition of the need to carefully classify the spectrum of these observations. Many questions about the pathogenesis of J-wave patterns, and the associated magnitudes of risk, remain unanswered, especially in regard to the risk implications in certain high-prevalence subpopulations such as athletes, children, and adolescents. Interest in these electrocardiography (ECG) patterns has grown dramatically in recent years, in large part because of the frequency with which these patterns are observed on routine ECGs. In this review, we discuss the current knowledge on the prevalence of different J-point/J-wave patterns and estimates of the magnitude of mortality and SCD risk associated with J-point elevations and J-waves, in what has become known as ER patterns.
To determine the anti-inflammatory effect and safety of hydroxychloroquine after acute myocardial infarction.
In this multicenter, double-blind, placebo-controlled OXI trial, 125 myocardial ...infarction patients were randomized at a median of 43 h after hospitalization to receive hydroxychloroquine 300 mg (n = 64) or placebo (n = 61) once daily for 6 months and, followed for an average of 32 months. Laboratory values were measured at baseline, 1, 6, and 12 months.
The levels of interleukin-6 (IL-6) were comparable at baseline between study groups (p = 0.18). At six months, the IL-6 levels were lower in the hydroxychloroquine group (p = 0.042, between groups), and in the on-treatment analysis, the difference at this time point was even more pronounced (p = 0.019, respectively). The high-sensitivity C-reactive protein levels did not differ significantly between study groups at any time points. Eleven patients in the hydroxychloroquine group and four in the placebo group had adverse events leading to interruption or withdrawal of study medication, none of which was serious (p = 0.10, between groups).
In patients with myocardial infarction, hydroxychloroquine reduced IL-6 levels significantly more than did placebo without causing any clinically significant adverse events. A larger randomized clinical trial is warranted to prove the potential ability of hydroxychloroquine to reduce cardiovascular endpoints after myocardial infarction.
•The first randomized trial of hydroxychloroquine in patients with a recent myocardial infarction.•Hydroxychloroquine reduced IL-6 levels more than placebo when treatment was continued six months.•Treatment with hydroxychloroquine was safe.•The number of adverse events did not differ between the hydroxychloroquine and placebo groups.•A larger trial is warranted to prove if hydroxychloroquine can reduce cardiovascular endpoints.
Spatial QRS-T angle measured from a 12-lead electrocardiogram (ECG) has been shown to predict cardiac mortality. However, there is a paucity of studies on the prognostic significance of frontal QRS-T ...angle, which is more readily available from the standard 12-lead ECG. The purpose of the present study was to investigate the importance of wide frontal QRS-T angle, QRS-axis, and T-wave axis as cardiac risk predictors in general population.
We evaluated the 12-lead ECGs of 10 957 Finnish middle-aged subjects from the general population recorded between 1966 and 1972, and followed them for 30 ± 11 years. QRS-T angle 0 to 90°, QRS-axis -30 to 90°, and T-wave axis 0 to 90° were considered normal. The primary endpoint was death from arrhythmia, and the secondary endpoints were all-cause mortality and non-arrhythmic cardiac mortality. QRS-T angle ≥ 100° was present in 2.0% of the subjects, and it was associated with an increased risk of sudden arrhythmic death relative risk (RR) 2.26; 95% confidence interval (CI) 1.59-3.21; P< 0.001) and all-cause mortality (RR 1.57; CI 1.34-1.84; P< 0.001), but not with non-arrhythmic cardiac mortality (RR 1.34; CI 0.93-1.92; P= 0.13). The prognostic significance of wide QRS-T angle was mainly due to abnormal T-wave axis, which predicted death from arrhythmia (RR 2.13; CI 1.63-2.79; P< 0.001), all-cause mortality (RR 1.39; 1.24-1.55; P< 0.001), and non-arrhythmic cardiac death (RR 1.87; CI 1.50-2.34; P< 0.001).
Frontal QRS-T angle ≥ 100° increases the risk of arrhythmic death, this being mainly the result of an altered T-wave axis.
Aims To determine whether risk stratification tests can predict serious arrhythmic events after acute myocardial infarction (AMI) in patients with reduced left ventricular ejection fraction (LVEF ≤ ...0.40). Methods and results A total of 5869 consecutive patients were screened in 10 European centres, and 312 patients (age 65 ± 11 years) with a mean LVEF of 31 ± 6% were included in the study. Heart rate variability/turbulence, ambient arrhythmias, signal-averaged electrocardiogram (SAECG), T-wave alternans, and programmed electrical stimulation (PES) were performed 6 weeks after AMI. The primary endpoint was ECG-documented ventricular fibrillation or symptomatic sustained ventricular tachycardia (VT). To document these arrhythmic events, the patients received an implantable ECG loop-recorder. There were 25 primary endpoints (8.0%) during the follow-up of 2 years. The strongest predictors of primary endpoint were measures of heart rate variability, e.g. hazard ratio (HR) for reduced very-low frequency component (<5.7 ln ms2) adjusted for clinical variables was 7.0 (95% CI: 2.4–20.3, P < 0.001). Induction of sustained monomorphic VT during PES (adjusted HR = 4.8, 95% CI, 1.7–13.4, P = 0.003) also predicted the primary endpoint. Conclusion Fatal or near-fatal arrhythmias can be predicted by many risk stratification methods, especially by heart rate variability, in patients with reduced LVEF after AMI.
Abstract
Background
Heart failure (HF) is one the leading causes of hospitalization in the Western world. Women have a lower rate of HF hospitalization and mortality compared to men. Role of 12-lead ...electrocardiography (ECG) as a risk marker of future HF in women is not well known.
Purpose
We studied the association of standard 12-lead ECG and clinical risk factors to HF hospitalization in women and in men separately from a large middle aged general population sample with a long-term follow-up.
Methods
Standard 12-lead ECG markers were analyzed from 10,864 subjects (48.8% women, N=5,215) of the prospective Mobile Clinic Study, and their predictive value for HF hospitalization was analyzed.
Results
During the follow-up (29.6±11.2 yrs.), a total of 1,743 subjects had HF hospitalization; out of these, 861 were women (49.4%). Several baseline characteristics, such as age, body mass index, blood pressure, and history of prior cardiac disease predicted the occurrence of HF both in women and men (P<0.001 for all). After adjusting for baseline variables, ECG sign of left ventricular hypertrophy (LVH) (P<0.001), and atrial fibrillation (P<0.001) were the only baseline ECG variables that predicted the future HF in women. In men, HF was predicted by fast heart rate (P=0.008), T wave inversions (P<0.001), abnormal Q waves (P=0.002), and atrial fibrillation (P<0.001). Statistically significant gender interactions in prediction of HF were observed in ECG sign of LVH (P<0.001), inferolateral T wave inversions (P=0.005), and heart rate (P=0.012).
Conclusions
ECG sign of LVH predicts future HF in middle-aged women independently, and T wave inversions and elevated heart rate are associated with HF hospitalization in men in.
Acknowledgement/Funding
Finnish Cultural Foundation, The University of Oulu Scholarship Foundation, Juho Vainio Foundation
Short QT syndrome (SQTS) is a rare arrhythmogenic inherited heart disease. Diagnosis can be challenging in subjects with slightly shortened QT interval at electrocardiogram. In this study we compared ...the QT interval behaviour during exercise in a cohort of SQTS patients with a control group, to evaluate the usefulness of exercise test in the diagnosis of SQTS.
Twenty-one SQTS patients and 20 matched control subjects underwent an exercise test. QT interval was measured at different heart rates (HRs), at rest and during effort. The relation between QT interval and HR was evaluated by linear regression analysis according to the formula: QT = β ×HR + α, where β is the slope of the linear relation, and α is the intercept. Rest and peak exercise HRs were not different in the two groups. Short QT syndrome patients showed lower QT intervals as compared with controls both at rest (276 ± 27 ms vs. 364 ± 25 ms, P < 0.0001) and at peak exercise (228 ± 27 ms vs. 245 ± 26 ms, P = 0.05), with a mean variation from rest to peak effort of 48 ± 14 ms vs. 120 ± 20 ms (P < 0.0001). Regression analysis of QT/HR relationship revealed a less steep slope for SQTS patients compared with the control group, never exceeding the value of -0.90 ms/beat/min (mean value -0.53 ± 0.15 ms/beat/min vs. -1.29 ± 0.30 ms/beat/min, P < 0.0001).
Short QT syndrome patients show a reduced adaptation of the QT interval to HR. Exercise test can be a useful tool in the diagnosis of SQTS.
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