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QRS interval [keywords]
- Associations of Electrocardiographic P-wave Characteristics with Left Atrial Structure, Function and Diffuse Left Ventricular Fibrosis Defined by Cardiac Magnetic Resonance: the PRIMERI Study. [JOURNAL ARTICLE]
- Heart Rhythm 2014 Sep 26.
Abnormal P-terminal force in V1 (PTFV1) is associated with an increased risk of heart failure, stroke, atrial fibrillation (AF) and death.Our goal was to explore associations of left ventricular (LV) diffuse fibrosis with left atrium (LA) function and ECG measures of LA electrical activity.AF-free patients (n=91, mean age 59.5, 61.5% men, 65.9% Caucasian) with structural heart disease (wide spatial QRS-T angle≥105° ± Selvester QRS score≥5 on ECG) but LV ejection fraction >35% underwent clinical evaluation, cardiac magnetic resonance and resting ECG. LA function indices were obtained by multimodality tissue tracking using 2 and 4-chamber long-axis images. T1 mapping and late gadolinium enhancement were used to assess diffuse LV fibrosis and presence of scar. P-prime in V1 amplitude (PPaV1) and duration (PPdV1), averaged P-duration, PR interval and P-axis were automatically measured using 12SL TM algorithm. PTFV1 was calculated as product of PPaV1 by PPdV1. RESULTS: In linear regression after adjustment for demographic, body mass index, LA volumemax index, presence of scar and LV mass index, each decile increase in LV interstitial fibrosis was associated with 0.76mV*ms increase in negative abnormal PTFV1 [(95%CI -1.42 to -0.09), P=0.025], 15.3ms prolongation in PPdV1 [(95%CI 6.9 to 23.8), P=0.001], and 5.4ms widening in averaged P-duration [(95%CI 0.9 to10.0), P=0.020]. LV fibrosis did not affect LA function. PPaV1 and PTFV1 were associated with an increase in LA volumes, decrease in LAEF and LA reservoir function.LV interstitial fibrosis is associated with abnormal PTFV1, prolonged PPdV1 and P-duration, but does not affect LA function.
- Presence of Septal Q Waves in a Patient with WPW and Manifest Preexcitation. [JOURNAL ARTICLE]
- Ann Noninvasive Electrocardiol 2014 Sep 30.
Wolff-Parkinson-White syndrome (WPW) is characteristically diagnosed by the presence of a short PR interval, a delta wave, and a wide QRS wave on the surface ECG. In the absence of these clear criteria, absent septal Q waves have been used as additional evidence suggestive of subtle preexcitation. We report a patient with WPW and manifest anteroseptal (AS) accessory pathway who had prominent septal Q waves on the surface ECG. This case highlights that physicians should be careful not to dismiss preexcitation in the presence of septal Q waves.
- Comparative Effectiveness of Cardiac Resynchronization Therapy in Combination With Implantable Defibrillator in Patients With Heart Failure and Wide QRS Duration. [JOURNAL ARTICLE]
- Am J Cardiol 2014 Aug 27.
Several clinical trials have established that cardiac resynchronization therapy in combination with an implantable cardioverter-defibrillator improves survival and alleviates heart failure symptoms in appropriately selected patients. Recent guidelines have expanded the indications to include patients with less severe heart failure. The aim of this study was to examine the extent to which cardiac resynchronization therapy in combination with an implantable cardioverter-defibrillator improves survival and reduces risk for heart failure hospitalization in United States Medicare patients who met class I or class IIa recommendations. Propensity score methods were used to assess survival and rehospitalization outcomes in Medicare patients. Among patients who met class I recommendations, those with combined cardiac resynchronization therapy had significantly lower risk for death (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.77 to 0.88, p <0.0001) and lower risk for rehospitalization (HR 0.88, 95% CI 0.83 to 0.94, p <0.0001). Among patients who met class IIa recommendations, the relative hazard of death for patients with combined cardiac resynchronization therapy was lower (HR 0.90, 95% CI 0.85 to 0.96, p = 0.0015), but there was no significant difference in the risk for rehospitalization for heart failure (HR 1.03, 95% CI 0.97 to 1.10, p = 0.2600). In conclusion, cardiac resynchronization therapy in combination with an implantable cardioverter-defibrillator resulted in improved survival among Medicare patients meeting class I criteria and most patients meeting class IIa criteria as outlined in the current guidelines for device-based therapy in heart failure, although the effect sizes were lower than those demonstrated in recent trials.
- Women with nonischemic cardiomyopathy have a favorable prognosis and a better left ventricular remodeling than men after cardiac resynchronization therapy. [JOURNAL ARTICLE]
- J Cardiovasc Med (Hagerstown) 2014 Sep 12.
Cardiac resynchronization therapy (CRT) is a well established therapy in heart failure patients who are on optimal medical therapy and have reduced left ventricular ejection fraction (LVEF) and wide QRS complexes. Although women and patients with nonischemic cardiomyopathy are under-represented in CRT trials and registries, there is evidence that these two groups of patients can benefit more from CRT. The aim of our analysis was to investigate the impact of female sex on mortality in a population that included a high percentage of patients (61%) with nonischemic cardiomyopathy.We analyzed data on 507 consecutive patients (20% women) who received CRT at two Italian Heart Transplant centers and were followed up for a maximum of 48 months.After multivariate adjustment, women showed a trend toward better survival with regard to all-cause mortality [hazard ratio (HR) 0.32, confidence interval (CI) 0.10-1.04; P = 0.059]. However, this benefit was limited to nonischemic patients with regard to all-cause mortality (HR 0.20, CI 0.05-0.87, P = 0.032) and cardiovascular mortality (HR 0.14, CI 0.02-1.05, P = 0.056).Female CRT recipients, at mid-term, have a favorable prognosis than male patients and this benefit appears to be more evident in nonischemic patients. Thus, we strongly believe that the apparent under-utilization of CRT in females is an anomaly that should be corrected.
- A pediatric case of Brugada syndrome diagnosed by fever-provoked ventricular tachycardia. [Journal Article]
- Korean J Pediatr 2014 Aug; 57(8):374-8.
Brugada syndrome is a rare channelopathy associated with the SCN5A gene that causes fatal ventricular arrhythmias. This case of Brugada syndrome, in which ventricular tachycardia (VT) was provoked by high fever, is the first report in a Korean child. The boy had retinoblastoma of his left eye diagnosed at 16 months of age. After chemotherapy, he contracted a catheter-related infection with a high fever up to 41℃ leading to monomorphic VT. This was characterized as having right bundle branch block morphology, superior axis deviation, and a heart rate of 212/min. Direct current cardioversion recovered the VT to sinus rhythm after a lack of response to amiodarone and lidocaine. A second attack of VT that was not controlled by cardioversion, however, responded to lidocaine. The baseline electrocardiogram showed a long PR interval and QRS duration, and the patient's grandfather had a history of Brugada syndrome. A mutation in SCN5A was identified in this patient, his father, and his grandfather. The patient was treated with quinidine and followed up for 1 year.
- Frequency, origin, and outcome of ventricular premature complexes in patients with or without heart diseases. [Journal Article]
- Am J Cardiol 2014 Nov 1; 114(9):1373-8.
The objective of the present study was to investigate the relation of ventricular premature complex (VPC) burden, origin, and electrocardiographic characteristics with left ventricular function and survival. Of 1,589 study patients, 388 (25%), 610 (38%), and 591 (37%) had low (<1,000/24 hours), moderate (1,000 to 10,000/24 hours), and high (>10,000/24 hours) VPC burden, respectively. Twenty-three percent of study patients had a left ventricular (LV) ejection fraction <50% (8% in low-, 20% in moderate-, and 36% in high-VPC-burden groups, p <0.001). High VPC burden was associated with lower LV ejection fraction in the presence (r = -0.17, p <0.001) and absence (r = -0.20, p <0.001) of heart diseases. The Kaplan-Meier survival estimates showed a significant difference among the 3 VPC burden groups (p = 0.046). The survival rates were significantly lower for patients with a VPC coupling interval of ≥480 ms than those with a VPC coupling interval of <480 ms (p = 0.002) and lower for those with a VPC QRS duration of ≥150 ms than those with a VPC QRS duration of <150 ms (p <0.001). In conclusion, high VPC burden is detrimental to LV systolic function. Broader VPC QRS duration and longer VPC coupling interval adversely impact on long-term survival.
- The Effect of Hemodialysis on Electrocardiographic Parameters. [JOURNAL ARTICLE]
- Ann Noninvasive Electrocardiol 2014 Sep 9.
Cardiovascular complications are the leading causes of premature deaths in hemodialysis patients. Due to rapid changes in volume and electrolyte concentration following dialysis, the some electrocardiographic (ECG) changes or arrhythmias might be seen.To investigate the acute effects of hemodialysis on the ECG parameters in patients with chronic end-stage renal disease (ESRD).We included the consecutive ESRD patients who underwent a hemodialysis. Before and after hemodialysis, some 12 lead ECG parameters were analyzed by two different cardiologists by using electronic digital caliper device.A total of 62 patients (mean 52 ± 15 years; 65% male) with ESRD undergoing hemodialysis were recruited to the study. P-wave amplitude, QRS amplitude, QRS duration, QTc dispersion, the sum of amplitudes in V1S + V5R derivations, total QRS amplitude, and duration were significantly greater in posthemodialysis patients compared to the prehemodialysis ones. However, T-wave amplitude and QTc duration were significantly lower in posthemodialysis patients.The ECG changes including prolangated QRS and increased QTc interval after hemodialysis should be kept in mind and assessed carefully in ESRD patients. Prolongation of these parameters may prove to be a further noninvasive marker of susceptibility to ventricular arrhythmias.
- QRS morphology and ventricular dyssynchrony in patients with chronic right ventricular pacing. [Journal Article]
- Int J Cardiol 2014 Oct 20; 176(3):962-8.
Mechanical dyssynchrony (MD) is associated with poor outcomes in many different populations. However, the predictors for the development of MD after chronic right ventricular (RV) pacing are not well known.Pacing QRS morphology and MD using echocardiography was analyzed in 175 consecutive patients that have pacemaker implantation during a 7.6year median follow-up. Predictive score for MD was constructed using QRS morphology variables and calculated by summing the points of the 4 variables: duration (≥150ms, 1 point), transition (1 point), notching (2 points), and left-axis deviation (1 point), based on a multivariate-adjusted risk relationship with MD.Sixty-eight (38.9%) patients developed MD. Patients with MD had worsened left ventricular systolic function (ejection fraction from 64.6±10.6% to 59.1±10.4%, p<0.001) and heart failure symptoms (New York Heart Association functional class increase from 1.1±0.3 to 1.9±0.8, p<0.001). In an electrocardiographic analysis, QRS duration ≥150ms, the presence of precordial axis transition, notching, and left-axis deviation were strongly associated with MD. Predictive score for MD using QRS morphology parameters displayed an excellent graded relationship with MD (score 0: 3.4% vs. 1: 12.5% vs. 2: 22.6% vs. 3: 45.0% vs. 4: 57.9% vs. 5: 72.7%, linear p<0.001) (model performance c-static 0.78, 95% confidence interval 0.72-0.85, p<0.001).Patients with MD experienced a decline in left ventricular systolic function and an increase in heart failure symptoms after chronic RV pacing. A new scoring system using QRS morphology is considered a simple and efficient tool for predicting the development of MD after chronic RV pacing.
- Normal electrocardiographic and echocardiographic (M-mode and two-dimensional) values in Polish Landrace pigs. [JOURNAL ARTICLE]
- Acta Vet Scand 2014; 56(1):54.
Swine are recognized animal models of human cardiovascular diseases. Normal values of cardiac morphology and function have been published for swine but for smaller number of pigs and not for swine whose weights ranged up 100 kg. In order to improve the value of results of an investigation on cardiac morphology and function in swine when such data are extrapolated to humans, the aim of this study was to document electrocardiographic and echocardiographic measures of cardiac morphology and function in swine. The study comprised 170 single and repeated measurements that were made in 132 healthy domestic swine (Sus domesticus) whose weights ranged between 20-160 kg and were used as controls in three different experiments. All electrocardiographic and echocardiographic measurements in all swine were done under general anaesthesia.Statistically significant correlations were found between body weight and heart rate (HR), the duration of the P-wave, the duration of the QRS interval, the duration of the QT interval, and the corrected QT ratio (QTc). Since body weight was positively correlated with age, statistically significant correlations were also found between age and HR, the duration of the P-wave, the duration of the QRS interval, the duration of the QT interval, and the QTc. We found that the thickness of the left ventricular wall and the internal diameter of the left ventricle increased with age and body weight. We also found positive trends between body weight and ejection fraction and body weight and fractional shortening. We also found a positive relationship between age, body weight, and the ratio of the left ventricular internal diameter to its wall thickness, as well as the relative left atrial size.Many electro- and echocardiographic measures of cardiac morphology and function of healthy swine are related to their body weight. When the electro- and echocardiographic measures of domestic swine and humans are compared, the most comparable electrocardiographic values are those that were determined in swine whose body weights are not greater than 70 kg. In contrast, the most comparable echocardiographic measures are those that were determined in swine with a body weight of 40-110 kg.
- Normal values of the electrocardiogram for ages 16-90years. [JOURNAL ARTICLE]
- J Electrocardiol 2014 Aug 2.
To establish an up-to-date and comprehensive set of normal values for the clinically current measurements in the adult ECG, covering all ages for both sexes.The study population included 13,354 individuals, taken from four population studies in The Netherlands, ranging in age from 16 to 90years (55% men) and cardiologically healthy by commonly accepted criteria. Standard 12-lead ECGs were available for all participants. The ECGs were processed by a well-validated computer program. Normal limits were taken as the 2nd and 98th percentiles of the measurement distribution per age group.Our study corroborates many findings of previous studies, but also provides more differentiated results, in particular for the older age groups. Age trends were apparent for the QTc interval, QRS axis, and indices of left ventricular hypertrophy. Amplitudes in the left precordial leads showed a substantial increase in the older age groups for women, but not for men. Sex-dependent differences were apparent for most ECG parameters. All results are available on the Website www.normalecg.org, both in tabular and in graphical format.We determined age- and sex-dependent normal values of the adult ECG. Our study distinguishes itself from other studies by the large size of the study population, comprising both sexes, the broad range of ages, and the exhaustive set of measurements. Our results emphasize that most diagnostic ECG criteria should be age- and sex-specific.