Left ventricular diastolic dysfunction is associated with impaired baroreflex at rest and during orthostatic stress in hypertensive patients with left ventricular hypertrophy.

The study aimed to determine the relationship between left ventricular (LV) diastolic function and the heart's spontaneous baroreflex at rest and in response to orthostatic stress during a prospective follow-up of hypertensive patients with LV hypertrophy (LVH+). LV structure and function and baroreflex sensitivity (BRS) during tilt testing were evaluated in 24 LVH+ patients and compared with 25 age-matched healthy controls and 25 hypertensive patients without LVH (LVH-). Clinical status, diastolic function and BRS were then assessed in LVH+ patients during treatment with telmisartan (monotherapy or combined with hydrochlorothiazide and/or amlodipine) at 6- and 18-month follow-ups. LVH+ patients had significantly altered diastolic function indices and decreased BRS as compared with healthy controls and LVH- patients. During the 18-month follow-up, favorable changes in diastolic function were associated with improvement in BRS at rest and during tilting. In multivariate regression models, an index reflecting rate of LV myocardial relaxation (E'sept) where E'sept denotes peak early diastolic velocity at the septal mitral annulus and a surrogate for LV filling pressure (E/E'sept), independently from other clinical and echocardiographic variables related to the low-frequency component of BRS during tilting. In conclusion, the LV diastolic function indices have independent associations with BRS parameters obtained at rest and during orthostatic stress in LVH+ patients receiving long-term pharmacological intervention.

The association between pathological internet use and comorbid psychopathology: a systematic review.

BACKGROUND: Pathological Internet use (PIU) has been conceptualized as an impulse-control disorder that shares characteristics with behavioral addiction. Research has indicated a potential link between PIU and psychopathology; however, the significance of the correlation remains ambiguous. The primary objective of this systematic review was to identify and evaluate studies performed on the correlation between PIU and comorbid psychopathology; the secondary aims were to map the geographical distribution of studies, present a current synthesis of the evidence, and assess the quality of available research. SAMPLING AND METHODS: An electronic literature search was conducted using the following databases: MEDLINE, PsycARTICLES, PsychINFO, Global Health, and Web of Science. PIU and known synonyms were included in the search. Data were extracted based on PIU and psychopathology, including depression, anxiety, symptoms of attention deficit and hyperactivity disorder (ADHD), obsessive-compulsive symptoms, social phobia and hostility/aggression. Effect sizes for the correlations observed were identified from either the respective publication or calculated using Cohen's d or R(2). The potential effect of publication bias was assessed using a funnel plot model and evaluated by Egger's test based on a linear regression. RESULTS: The majority of research was conducted in Asia and comprised cross-sectional designs. Only one prospective study was identified. Twenty articles met the preset inclusion and exclusion criteria; 75% reported significant correlations of PIU with depression, 57% with anxiety, 100% with symptoms of ADHD, 60% with obsessive-compulsive symptoms, and 66% with hostility/aggression. No study reported associations between PIU and social phobia. The majority of studies reported a higher rate of PIU among males than females. The relative risks ranged from an OR of 1.02 to an OR of 11.66. The strongest correlations were observed between PIU and depression; the weakest was hostility/aggression. CONCLUSIONS: Depression and symptoms of ADHD appeared to have the most significant and consistent correlation with PIU. Associations were reported to be higher among males in all age groups. Limitations included heterogeneity in the definition and diagnosis of PIU. More studies with prospective designs in Western countries are critically needed.

[The relation between QT dispersion and incidence of ventricular premature beats in patients after myocardial infarction]. / Zaleznosc pomiedzy dyspersja odstepu QT a wystepowaniem przedwczesnych pobudzen komorowych u chorych po przebytym zawale serca.

The relation between increased QT dispersion and ventricular arrhythmias in patients after myocardial infarction is not definitely confirmed. The diurnal variation and long-term changes in QT dispersion can be a substantial cause of conflicting results presented in follow-up studies that tested the prognostic significance of QT dispersion. The present study was designed to determine the relation between incidence of ventricular premature beats (VPBs) and magnitude of QT dispersion measured in sinus beats before VPBs occurrence. The study group consisted of 306 postinfarction patients including 153 patients with VPBs and 153 patients without VPBs on a routine ECG. QT dispersion was calculated as the difference between the maximum and the minimum QT intervals across a 12-lead ECG. In the group of patients with VPBs the mean value of QT dispersion was greater than in the group without VPBs (81 +/- 40 ms versus 56 +/- 33 ms, p < 0.0001). The results of univariate analysis indicated that QT dispersion > 60 ms, corrected QT interval > 465 ms, QRS complex > 100 ms and RR interval < or = 800 ms were all associated with VPBs incidence. Discriminant analysis of these variables revealed that QT dispersion > 60 ms was the strongest indicator of VPBs recorded on a routine ECG (F = 47.88; p < 0.0001). Increased QT dispersion is an electrocardiographic marker of susceptibility to ventricular premature beats in patients after myocardial infarction.

Predictive power of increased QT dispersion in ventricular extrasystoles and in sinus beats for risk stratification after myocardial infarction.

BACKGROUND: QT dispersion, commonly measured in sinus beats (QTd-S), can also be calculated in premature ventricular beats (QTd-V). To date, no studies have addressed the relation between these 2 variables. METHODS AND RESULTS: In 148 patients with remote myocardial infarction and premature ventricular beats on a routine ECG, QT dispersion, defined as the difference between the maximum and the minimum QT interval across the 12-lead ECG, was calculated separately for the ventricular extrasystole and the preceding sinus beat. In the total group of patients, QTd-V was greater than QTd-S (83+/-33 versus 74+/-34 ms, respectively; P=0.001). During a follow-up period of 35+/-17 months, arrhythmic events (sustained ventricular tachycardia, ventricular fibrillation, or sudden death) were noted in 30 patients. A QTd-V of >/=100 ms was a stronger univariate marker of arrhythmic events than was a QTd-S of >/=100 ms, and multivariate analysis selected only prolonged QTd-V (hazard ratio 3.81, 95% CI 2.2 to 11.2) and low ejection fraction (hazard ratio 3.05, 95% CI 1.6 to 7.6) as independent predictors of arrhythmic events. CONCLUSIONS: The magnitude of QTd-V was greater than that of QTd-S in the total group of patients. Prolonged QTd-V is associated with a significantly increased risk for arrhythmic events in postinfarction patients, and the prognostic significance of QTd-V exceeds that of QTd-S.

Dispersion of QT interval following ventricular premature beats and mortality after myocardial infarction.

In a group of 193 postinfarction patients with ventricular premature beats on a resting 12-lead ECG, the dispersion of QT and JT intervals was calculated as a difference between maximum and minimum QT and JT intervals in ventricular premature beats. During a follow-up of 38 +/- 17 months, death from all causes was noted in 56 patients. Univariate predictors of mortality included QT dispersion >/=100 ms, JT dispersion >/=100 ms, left ventricular ejection fraction <40%, complete bundle branch block, 'R-on-T' index of ventricular premature beats <1 and age of patients >60 years. At multivariate Cox proportional hazards survival analysis, only QT dispersion >/=100 ms, left ventricular ejection fraction <40% and complete bundle branch block had an independent relation to postinfarction mortality. The final model selected increased QT dispersion as the prognostic factor which was the most strongly related to mortality (chi(2) = 23.60, p = 0.0000).

Dispersion of QT interval in premature ventricular beats as a marker of susceptibility to arrhythmic events.

BACKGROUND: Clinical observations indicate that increased QT interval dispersion in sinus beats may portend malignant ventricular arrhythmias and sudden cardiac death. The purpose of this study was to test the hypothesis that measures of QT dispersion in ventricular premature beats (QTd-V) may be also useful in identifying patients at high risk of arrhythmic events. METHODS: In the group of 303 patients with ventricular premature beats on standard 12-lead ECG, the QTd-V was calculated as a difference between maximum and minimum QT interval in premature ventricular beats. During follow-up for 26 +/- 19 months the arrhythmic events (sustained ventricular tachycardia, ventricular fibrillation or sudden cardiac death) were noted in 42 patients. RESULTS: Patients with arrhythmic events had significantly (P < 0.005) greater values of QTd-V than those without arrhythmic events. Univariate predictors of arrhythmic events included QTd-V > or = 100 ms, left ventricular ejection fraction < 40%, QRS complex duration of ventricular premature beats > 150 ms, underlying heart disease and complete bundle branch block. Multivariate analysis using the Cox proportional hazard model showed that only QTd-V > or = 100 ms and ejection fraction < 40% were independent predictors of arrhythmic events. CONCLUSIONS: The results of this study indicate a significant relationship between QTd-V and the risk of arrhythmic events. The assessment of QTd-V may be useful for identifying patients with ventricular premature beats at high and low risk of subsequent arrhythmic events.

Low variability of cycle lengths in nonsustained ventricular tachycardia as an independent predictor of mortality after myocardial infarction.

In a group of 191 postinfarction patients, the low variability of cycle lengths in nonsustained ventricular tachycardia was associated with poor prognosis during follow-up. By use of Cox model analysis it was found that reduced ventricular rate variability was a powerful independent predictor of sudden death and all-cause mortality in this group of patients.

24-h ECG monitoring in patients with rheumatoid arthritis.

Although the main cardiac complication in patients with rheumatoid arthritis is subclinical pericarditis, mononuclear cell infiltrations into myocardium may cause cardiac arrhythmias and conduction defects. In order to examine these problems we evaluated 70 patients (53 women and 17 men) aged 18-83 years (average 56.7 +/- 11.2) with classic or definite rheumatoid arthritis, according to diagnostic criteria. Duration of the disease was 1-35 years (average 8.7 +/- 8.4). The control group comprised 70 patients admitted to hospital with degenerative joint disease, a duodenal ulcer, or who required treatment for ophthalmological or laryngeal reasons; these patients were matched for sex and age. In all patients standard 12-lead ECG investigations were performed, as well as 24-h ECG monitoring, using an Oxford Medical System device with two precordial leads CM5 and CS2, according to the Holter method. We analysed heart rate, conduction disturbances, and occurrence of arrhythmias, on the basis of generally assumed ECG criteria. Cardiac arrhythmias were found in 50% of patients with rheumatoid arthritis, and their occurrence was similar to that in the control group. Observed arrhythmias were independent of the progression of arthritis, the type of treatment administered, the familial occurrence of arthritis, the presence of manifestations pertaining to organs, the presence of rheumatoid factor, the stage of the disease according to Steinbrocker, or the presence of immune complexes in serum and HLA Dr antigens, which are regarded as fundamental in the pathogenesis of rheumatoid arthritis.

[Diurnal variability of heart rate during paroxysmal ventricular tachycardia]. / Zmiennosc dobowa czestotliwosci rytmu serca podczas napadowego czestoskurczu komorowego.

The aim of this study was to assess the diurnal variability of heart rate during VT. For the purpose of this investigation VT was considered to be a minimum of 3 consecutive ventricular beats in duration at a rate more than 100 bpm. From the group of 287 patients with VT during 24-hour ECG monitoring, a selection was made of 52 patients in whom episodes of monomorphic VT occurred in the day-time and night-time without any changes of the QRS morphology. Thirty one patients had ischemic heart disease, 10--dilated cardiomyopathy, 2--mitral valve prolapse and 10 patients had no evidence of heart disease. In these patients the rate of VT (HR-V), basic heart rate (HR-S) before VT, and coupling interval (CI) of VT initiating beat were measured during day-time and night-time. The mean VT rate was 170 +/- 34 bpm during day-time and 149 +/- 36 bpm during night-time (p < 0.001). The mean sinus rhythm rate was significantly (p < 0.001) greater during day-time (88 +/- 16 bpm) than at night (78 +/- 19 bpm). There was significant difference in the mean values of the CI between day-time and night-time (504 +/- 122 vs 589 +/- 181 ms). A significant correlation was noted between HR-V and HR-S at night (r = 0.73; p < 0.001) but not during day-time (r = 0.38). Thus, HR-V similarly as HR-S is greater during day-time than during night-time. Diurnal variability of HR-V may be related to changes in autonomic nervous system tone.