Sep 2, 2014 - Heart Association Class III-IV decompensated systolic heart failure symptoms were included in this study. Initial and post-treatment.
Acta Medica Mediterranea, 2015, 31: 137
QT INTERVAL CHANGES DURING THE MANAGEMENT OF DECOMPENSATED HEART FAILURE IN THE EMERGENCY CARE SETTING
ERKAN TEMIZKAN1, MEHMET UNALDI1, FIKRET BILDIK2, AHMET DEMIRCAN2, AYFER KELES2, ISA KILICARSLAN2, HATICE ERYIGIT3 ¹Medipol University Medical Faculty, Department of Emergency Medicine, Istanbul - 2Gazi University Medical Faculty, Department of Emergency Medicine, Ankara - 3Lutfi Kirdar Kartal Training and Research Hospital, Department of Thoracic Surgery, Istanbul, Turkey
ABSTRACT Introduction: Reliable and objective diagnostic tools are needed for heart failure to assist prompt intervention, diagnosis, treatment, and admission and/or discharge decisions in the emergency room. The aim of this study was to assess the treatment-associated changes in corrected QT interval in patients with decompensated heart failure in the emergency care setting. Materials and methods: Thirty-nine adult patients with known heart failure presenting to the emergency room with New York Heart Association Class III-IV decompensated systolic heart failure symptoms were included in this study. Initial and post-treatment electrocardiography recordings were examined for corrected QT interval changes. Results: Treatment of decompensated heart failure resulted in a statistically significant reduction in QT interval when compared to pre-treatment measurements: 432.3±43.3 (range, 320-508) vs. 486.3±44.1 (range, 414-600) milliseconds, p=0.001. Discussion: Monitoring corrected QT interval may represent a useful additional assessment tool that may aid in the assessment of decompensated heart failure patients in the emergency room and in the decision for admission and discharge. However, further studies are warranted.
Key words: decompensated heart failure, corrected QT interval, emergency care, treatment. Received May 18, 2014; Accepted September 02, 2014
Introduction Heart failure (HF) represents an important public health problem, particularly in the developed world, owing to its high prevalence and increasing incidence rates, poor prognosis, and the associated economic burden. In contrast with the decreased mortality of acute coronary syndrome in the last two decades due to advances in the field of medicine, HF mortality has remained stable with a 150% increase in hospital admissions(1-2). In addition to history and physical examination, radiological imaging studies, electrocardiography (ECG), and several biochemical tests are also commonly utilized for the emergency diagnostic work-up, treatment, and for the decision to admit or discharge patients with HF.
However, none of these is disease-specific for HF, warranting more reliable and objective diagnostic tools for prompt intervention, diagnosis, treatment, and admission and/or discharge decisions in the emergency room. Numerous studies examining the utility of ECG, a heart-specific assessment tool routinely used in HF patients, has been and is currently being carried out. In electrophysiological studies and animal experiments, heart failure is generally assumed to represent an acquired corrected QT (QTc) interval prolongation. Clinically, acquired QTc prolongation is thought to occur during the decompensation stage of heart failure, with an eventual shortening of QTc interval after compensation (3) . Monitoring QTc interval in decompensated HF patients presenting to the emergency room with
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dyspnea may represent an objective, feasible, and reliable method that may assist in quick differential diagnosis, treatment, and admission and discharge decisions. This study was undertaken to assess the treatment-associated changes in QTc interval in patients presenting to the emergency room with a previous diagnosis of decompensated heart failure. Materials and methods This prospective observational study was carried out between January 2013 and March 2013 in the Department of Emergency Medicine for Adult Patients and Coronary Care unit of our institution. The institutional ethics committee approved the study protocol; all the study procedures were conducted in accordance with the Declaration of Helsinki. All patients gave written informed consent prior to study entry.Table Patients Adult patients presenting to the emergency room with dyspnea, providing consent for study participation, and meeting the following eligibility criteria were included in the study: age > 18 years, prior diagnosis of heart failure, and presence of New York Heart Association (NYHA) Class III-IV decompensated heart failure symptoms. Exclusion criteria included: a preliminary diagnosis of heart failure that was subsequently ruled out; other causes of widened QRS complex such as left bundle branch block, pacemaker rhythm, ventricular tachycardia; current or recent use of cardiac or non-cardiac drugs known to be associated with prolonged QT interval; presence of ST elevation; electrolyte imbalance; pregnancy or breastfeeding; requirement for cardiopulmonary resuscitation (CPR); a diagnosis of diastolic heart failure (ejection fraction (EF) greater than 50%); and unwillingness to continue study participation at any stage of the study. Management Demographic and clinical characteristics were recorded at the time of emergency room consultation, and the initial ECG recordings were included in the study file for subsequent analyses. All patients were consulted by Cardiologists and admitted to the Coronary Intensive Care unit. An echocardiography was performed in each participant using a General Electric Medical Systems Ge Vingmed Ultrasound As Mod: VIVID 7 Dimension
Erkan Temizkan, Mehmet Unaldi et Al
device in order to ascertain the presence of systolic heart failure with regard to EF values. Patients with diastolic heart failure, as evidenced by an EF of greater than 50%, were excluded from the study. During the decompensated stage, standard treatment consisting of diuretics (parenteral furosemide) was given. In addition, vasodilators (parenteral isosorbide monohydrate) were administered when tolerated by the patients. Patients continued their existing therapies (e.g. angiotensin converting enzyme antagonists, angiotensin II receptor blockers etc.). If no improvement was observed in heart failure symptoms, digoxin was added to the treatment. After compensation was achieved, betablocker treatment was also given. Although betablockers and digoxin, which are commonly used by many HF patients, are associated with reduced QT interval, these were added to the protocol since they represent established treatment for the condition. An ECG was performed at the end of the treatment and the ECG recordings were kept in the study file. A telephone call was made after 6 months to collect information on clinical status and mortality. QT Measurement Pre- and post-treatment 12-lead ECG recordings were manually obtained at a speed of 25 mm/sec and amplitude of 10 mm/mV using a Nihon Kohden ECG-9020 K device. ECG recordings were scanned and transferred into digital environment, magnified (200%), and the analyses were performed in the electronic environment (visual determination “eyeball/caliper” technique) by manual ECG readings. QTc was defined as the interval between the start of the Q wave and end of T wave. In the presence of a U wave, the deepest point between T and U waves was accepted as the end of T wave. In derivations where the end of the T wave could not be determined no measurements were performed and the measurements in the nearest group derivations were used. In the 12-lead ECG, measurements were performed in at least seven derivations, including those considered most sensitive for QTc such as standard DI and aVL derivations and V4 chest derivation, with at least three of these measurements being performed in the precordial derivations. Average QTc length was calculated using Bazzet’s formula adjusted for heart rate. Statistical analyses Al data were analyzed using Statistical Package for Social Sciences (SPSS) for Windows
Qt Interval Changes During The Management Of Decompensated Heart Failure In The Emergency Care Setting
16.0 (SPSS Inc. Chicago, USA) software package. Pre- and post-treatment QTc intervals were compared using paired samples t test. A p value
