Increased QT interval variability index in acute alcohol withdrawal.
ABSTRACT Acute alcohol withdrawal is associated with increased cardiovascular mortality, most likely due to cardiac arrhythmias. As the QT interval reflects the most critical phase for the generation of reentry and thus for arrhythmia, we examined QT variability in patients suffering from acute alcohol withdrawal.
High resolution electrocardiographic recordings were performed in 18 male unmedicated patients suffering from acute alcohol withdrawal, 18 matched controls and 15 abstained alcoholics. From these, parameters of beat-to-beat heart rate and QT variability such as approximate entropy and QT variability index (QTvi) were calculated. Measures were correlated with the severity of withdrawal symptoms and with serum electrolyte concentrations.
Heart rate and QTvi were significantly increased in acute alcohol withdrawal. Abstained alcoholics did not significantly differ from controls. While QTvi correlated with the severity of alcohol withdrawal symptoms, the mean QT interval duration showed an inverse relationship with serum potassium concentrations.
Our data indicate increased QT variability and thus increased repolarization lability in acute alcohol withdrawal. This might add to the elevated risk for serious cardiac arrhythmias. In part, these changes might be related to increased cardiac sympathetic activity or low potassium, thus suggesting the latter as possible targets for adjuvant pharmacological therapy during withdrawal.
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ABSTRACT: BACKGROUND: Reduced cardio-vascular health has been found in patients suffering from alcohol dependence. Low cardio-respiratory fitness is an independent predictor of cardio-vascular disease. METHODS: We investigated physical fitness in 22 alcohol-dependent patients 10 days after acute alcohol withdrawal and compared results with matched controls. The standardized 6-min walk test (6 MWT) was used to analyze the relationship of autonomic dysfunction and physical fitness. Ventilatory indices and gas exchanges were assessed using a portable spiroergometric system while heart rate recordings were obtained separately. We calculated walking distance, indices of heart rate variability and efficiency parameters of heart rate and breathing. In addition, levels of exhaled carbon monoxide were measured in all participants to account for differences in smoking behaviour. Multivariate analyses of variance (MANOVA) were performed to investigate differences between patients and controls with regard to autonomic and efficiency parameters. RESULTS: Patients walked a significantly shorter distance in comparison to healthy subjects during the 6 MWT. Significantly decreased heart rate variability was observed before and after the test in patients when compared to controls, while no such difference was observed during exercise. The efficiency parameters indicated significantly reduced efficiency in physiological regulation when the obtained parameters were normalized to the distance. DISCUSSION: The 6 MWT is an easily applied instrument to measure physical fitness in alcohol dependent patients. It can also be used during exercise interventions. Reduced physical fitness, as observed in our study, might partly be caused by autonomic dysfunction, leading to less efficient regulation of physiological processes during exercise.Drug and alcohol dependence 05/2013; 132(3):505-512. · 3.60 Impact Factor
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ABSTRACT: Drug-induced long QT syndrome (diLQTS) leading to Torsade de Pointes (TdP) is a potentially lethal condition, which has led to several post-marketing drug withdrawals in the past decade. The true incidence of diLQTS/TdP is largely unknown. One explanation is under-reporting of this potentially life-threatening adverse event by physicians and other medical staff to pharmacovigilance agencies. To gain more insight into the incidence of diLQTS and TdP, the Berlin Pharmacovigilance Center (PVZ-FAKOS) has actively and prospectively identified patients who developed this particular type of drug-induced adverse event. Here, the basic characteristics of the affected patients are summarized and suspected drugs are discussed. Furthermore, an extrapolation of the Berlin incidence rates to the German Standard Population is presented.METHODS AND RESULTS: Using a Berlin-wide network of 51 collaborating hospitals (>180 clinical departments), adult patients presenting with long QT syndrome (LQTS/TdP) between 2008 and 2011 were identified by active surveillance of these hospitals. Drug exposures as well as other possible risk factors were obtained from the patient's files and in a face-to-face interview with the patient. One-hundred and seventy patients of possible LQTS/TdP were reported to the Pharmacovigilance Center of whom 58 cases were confirmed in a thorough validation process. The majority (66%) of these cases were female and 60% had developed LQTS/TdP in the outpatient setting. Thirty-five (60%) of 58 confirmed cases were assessed as drug-related based on a standardized causality assessment applying the criteria of the World Health Organization. Drugs assessed as related in more than two cases were metoclopramide, amiodarone, melperone, citalopram, and levomethadone. The age-standardized incidence of diLQTS/TdP in Berlin was estimated to be 2.5 per million per year for males and 4.0 per million per year for females.CONCLUSION: While European annual reporting rates based on spontaneous reports suggest an annual diLQTS/TdP incidence of 0.26 per million in Germany, we estimated a considerably higher incidence of diLQTS/TdP in an active surveillance approach. Further measures are warranted to better sensitize physicians against this potentially life-threatening drug-induced adverse event.Europace 07/2013; · 2.77 Impact Factor
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ABSTRACT: Habitual light to moderate alcohol intake (up to 1 drink per day for women and 1 or 2 drinks per day for men) is associated with decreased risks for total mortality, coronary artery disease, diabetes mellitus, congestive heart failure, and stroke. However, higher levels of alcohol consumption are associated with increased cardiovascular risk. Indeed, behind only smoking and obesity, excessive alcohol consumption is the third leading cause of premature death in the United States. Heavy alcohol use (1) is one of the most common causes of reversible hypertension, (2) accounts for about one-third of all cases of nonischemic dilated cardiomyopathy, (3) is a frequent cause of atrial fibrillation, and (4) markedly increases risks of stroke—both ischemic and hemorrhagic. The risk-to-benefit ratio of drinking appears higher in younger individuals, who also have higher rates of excessive or binge drinking and more frequently have adverse consequences of acute intoxication (for example, accidents, violence, and social strife). In fact, among males aged 15 to 59 years, alcohol abuse is the leading risk factor for premature death. Of the various drinking patterns, daily low- to moderate-dose alcohol intake, ideally red wine before or during the evening meal, is associated with the strongest reduction in adverse cardiovascular outcomes. Health care professionals should not recommend alcohol to nondrinkers because of the paucity of randomized outcome data and the potential for problem drinking even among individuals at apparently low risk. The findings in this review were based on a literature search of PubMed for the 15-year period 1997 through 2012 using the search terms alcohol, ethanol, cardiovascular disease, coronary artery disease, heart failure, hypertension, stroke, and mortality. Studies were considered if they were deemed to be of high quality, objective, and methodologically sound.Mayo Clinic Proceedings 01/2014; 89(3):382–393. · 5.79 Impact Factor
Michael Karl Boettger