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Ventricular tachycardia [keywords]
- Epidemiologic pattern of myocardial infarction and modeling risk factors relevant to in-hospital mortality: the first results from Iranian Myocardial Infarction Registry. [JOURNAL ARTICLE]
- Kardiol Pol 2014 Nov 27.
Myocardial infarction (MI) care and treatment contribute greatly to the patients' fatality and mortality. Assessing and monitoring mortalities and the effective factors are necessary in MI care and treatment programs. No comprehensive and population-based study has been yet conducted in Iran to determine the epidemiologic pattern of MI and particularly in-hospital mortality rate and the effective factors.This study was aimed to determine the epidemiologic pattern of MI based on person, time, place and mortality-associated risk factors.This was a prospective, population-based cohort study which analyzed the data of 20750 MI patients in Iran in 2012. MI was diagnosed based on ICD10: the codes I21 and I22. The cohort of the patients was defined in terms of the date at diagnosis, hospitalization, and the date at discharge (recovery or death due to MI). The in-hospital mortality rate was calculated by Cox regression. Univariate analysis and multiple logistic regression were used to determine the effective factors on the patients' mortality. The odds ratio (95% confidence interval [CI]) was reported using Stata software.The relative frequency of in-hospital mortality was 12.1%. The in-hospital mortality rate was higher in women than in men and 6.74 (95% CI, 6.4-7) of the patients were at risk. The highest relative frequency (13.2%) was obtained in January (11 Dey to 11 Bahman in Persian calendar) and the lowest (5.9%) in May (11 Ordibehest to 10 Khordad in Persian calendar). Age of over 84 years, female gender, educational level, smoking, lack of thrombolytic therapy, type 2 diabetes, chest pain prior to arriving in hospital, right bundle branch block, ventricular tachycardia, percutaneous coronary intervention, lateral MIs, and ST segment elevation myocardial infarction (STEMI) were determinants of in-hospital mortality in the patients. The relative frequency of mortality from STEMI and non STEMI was reported 83.7% and 16.3% respectively.STEMI, Lack of thrombolytic therapy, the age of over 84 years, and ventricular tachycardia have the greatest effect on in-hospital mortality in MI patients. The results of this study are helpful in planning for monitoring and promotion of healthcare of the patients.
- Members of the emergency medical team may have difficulty diagnosing rapid atrial fibrillation in Wolff-Parkinson-White syndrome. [JOURNAL ARTICLE]
- Cardiol J 2014 Nov 27.
Atrial fibrillation (AF) in patients with Wolff-Parkinson-White (WPW) syndrome is potentially life-threatening as it may deteriorate into ventricular fibrillation. The aim of this study was to assess whether the emergency medical team members are able to diagnose AF with a rapid ventricular response due to the presence of atrioventricular bypass tract in WPW syndrome.The study group consisted of 316 participants attending a national congress of emergency medicine. A total of 196 questionnaires regarding recognition and management of cardiac arrhythmias were distributed. The assessed part presented a clinical scenario with a young hemodynamically stable man who had a 12-lead electrocardiogram performed in the past with signs of pre-excitation, and who presented to the emergency team with an irregular broad QRS-complex tachycardia.A total of 71 questionnaires were filled in. Only one responder recognized atrial fibrillation due to WPW syndrome, while five other responders recognized WPW syndrome and paroxysmal supraventricular tachycardia or broad QRS-complex tachycardia. About 20% of participants did not select any diagnosis, pointing out a method of treatment only. The most common diagnosis found in the survey was ventricular tachycardia/broad QRS-complex tachycardia marked by approximately a half of the participants. Nearly 18% of participants recognized WPW syndrome, whereas atrial fibrillation was recognized by fewer than 10% of participants.Members of emergency medical teams have limited skills for recognizing WPW syndrome with rapid atrial fibrillation, and ventricular tachycardia is the most frequent incorrect diagnosis.
- Relationship between risk factors and in-hospital mortality due to myocardial infarction by educational level: a national prospective study in Iran. [JOURNAL ARTICLE]
- Int J Equity Health 2014 Nov 27; 13(1):116.
IntroductionSince no hospital-based, nationwide study has been yet conducted on the association between risk factors and in-hospital mortality due to myocardial infarction (MI) by educational level in Iran, the present study was conducted to investigate relationship between risk factors and in-hospital mortality due to MI by educational level.MethodsIn this nationwide hospital-based, prospective analysis, follow-up duration was from definite diagnosis of MI to death. The cohort of the patients was defined in view of the date at diagnosis, hospitalization and the date at discharge (recovery or in-hospital death due to MI). 20750 patients hospitalized for newly diagnosed MI between April, 2012 and March, 2013 comprised sample size. Totally, 2511 deaths due to MI were obtained. The data on education level (four-level) were collected based on years of schooling. To determine in-hospital mortality rate and the associated factors with mortality, seven statistical models were developed using Cox proportional hazards models.ResultsOf the studied patients, 9611 (6.1%) had no education. in-hospital mortality rate was 8.36 (95% CI: 7.81-8.9) in women and 6.12 (95% CI: 5.83-6.43) in men per 100 person-years. This rate was 5.56 in under 65-year-old patients and 8.37 in over 65-year-old patients. This rate in the patients with no, primary, high school, and academic education was respectively 8.11, 6.11, 4.85 and 5.81 per 100 person-years. Being woman, chest pain prior to arriving in hospital, lack of thrombolytic therapy, right bundle branch block, ventricular tachycardia, smoking and ST-segment elevation myocardial infarction were significantly associated with increased hazard ratio (HR) of death. The adjusted HR of mortality was 1.27 (95% CI: 1.06-1.52), 0.93 (95% CI: 0.77-1.13), 0.72 (95%CI: 0.57-0.91) and 0.82 (95%CI: 0.66-1.01) in the patients with respectively illiterate, primary, secondary and high school education compared to academic education.ConclusionA disparity was noted in post-MI mortality incidence in different educational levels in Iran. HR of death was higher in illiterate patients than in the patients with academic education. Identifying disparities per educational level could contribute to detecting the individuals at high risk, health promotion and care improvement by relevant planning and interventions in clinics and communities.
- Chest pain associated with moderator band pacing. [Journal Article]
- Tex Heart Inst J 2014 Sep; 41(5):551-3.
A 65-year-old man was evaluated for chronic chest pain that had been present for 8 years after placement of a dual-chamber implantable cardioverter-defibrillator to treat inducible ventricular tachycardia. Previous coronary angiography had revealed nonobstructive coronary artery disease and a left ventricular ejection fraction of 0.45 to 0.50, consistent with mild idiopathic nonischemic cardiomyopathy. Evaluation with chest radiography and transthoracic echocardiography showed the implantable cardioverter-defibrillator lead to be embedded within the right ventricle at the moderator band, which had mild calcification. Treatment included extraction of the dual-coil lead and placement of a new single-coil right ventricular lead at the mid septum. The patient had complete relief of symptoms after the procedure. This case shows that chest pain can be associated with the placement of a right ventricular implantable cardioverter-defibrillator lead in the moderator band and that symptomatic relief can occur after percutaneous lead extraction and the implantation of a new right ventricular lead to the mid septal region.
- Reentry Using Anatomically Determined Isthmuses: A Curable Ventricular Tachycardia in Repaired Congenital Heart Disease. [JOURNAL ARTICLE]
- Circ Arrhythm Electrophysiol 2014 Nov 24.
-Ventricular tachycardia (VT) is an important cause of late morbidity and mortality in repaired congenital heart disease (rCHD). The substrate often includes anatomical isthmuses that can be transected by radiofrequency catheter ablation (RFCA) similar to isthmus block for atrial flutter. This study evaluates the long-term efficacy of isthmus block for treatment of reentry VT in adults with rCHD.-Thirty-four patients (49±13 years, 74% male) with rCHD who underwent RFCA of VT in two centres were included. Twenty-two (65%) had a preserved left and right ventricular function. Patients were inducible for 1 (IQR 1-2) VT, median cycle length 295ms (IQR 242-346). Ablation aimed to transect anatomical isthmuses containing VT reentry circuit isthmuses. Procedural success was defined as non-inducibility of any VT and transection of the anatomical isthmus and was achieved in 25 (74%) patients. During long-term follow-up (46±29 months) all patients with procedural success (18/25 with ICDs) were free of VT recurrence but 7/18 experienced ICD related complications. One patient with procedural success and depressed cardiac function received an ICD shock for VF. None of the 18 patients (12/18 with ICDs) with complete success and preserved cardiac function experienced any ventricular arrhythmia. In contrast, VT recurred in 4/9 patients without procedural success. Four patients died from non-arrhythmic causes.-In patients with rCHD with preserved ventricular function and isthmus dependent reentry, VT isthmus ablation can be curative.
- Multiple manifested accessory atrioventricular pathways in a patient without obvious structural heart disease. [JOURNAL ARTICLE]
- J Cardiovasc Electrophysiol 2014 Nov 24.
A 53-year-old man was referred for treatment of pre-excitation syndrome, which was first diagnosed after having had cardioversion for pre-syncope due to atrial fibrillation. He had hypertension controlled with losantan. The ECG indicated multiple accessory pathways (APs), located on the tricuspid annulus (TVA). Echocardiography revealed a dilated left atrium and slight left ventricular hypertrophy (associated with hypertension) without Ebstein anomaly. The procedure was performed with a 3D mapping system (CARTO 3). Manifested APs were mapped and ablated at 8 o'clock, 6 o'clock and 4 o'clock on the TVA step by step with a 4-mm-tip catheter (Fig 1, TA 1-3). However, an irrigation ablation catheter was mandatory for the AP at 4 o'clock due to the limitation of power output by a slight diverticulum. A normal QRS wave was achieved after ablation of the fourth AP at 2 o'clock on the TVA (Fig 1, TA4). The fifth AP was unmasked by isoproterenol infusion and was abolished at 10 o'clock on the TVA (Fig 1, TA5). After a 40-minute observation period, the procedure was stopped. Unfortunately, pre-excitation reappeared 9 hours after the procedure. In the repeat procedure (1 month later), the recurrent AP was mapped and ablated at 10 o'clock on the TVA. Six months after the repeated procedure, the patient still had a normal QRS without pre-excitation. For multiple APs, it is important to recognize the possibility of multiple APs before procedure and to pay attention to the change of ECG morphology and the local A-V interval or conduction during operation. With the help of a 3D mapping system, it would be feasible to precisely identify the location of multiple APs. This article is protected by copyright. All rights reserved.
- Ventricular Arrhythmia Risk Stratification in Patients with Tetralogy of Fallot at the Time of Pulmonary Valve Replacement. [JOURNAL ARTICLE]
- Circ Arrhythm Electrophysiol 2014 Nov 21.
-Most patients with repaired tetralogy of Fallot (TOF) require pulmonary valve replacement (PVR), but the evaluation for and management of ventricular arrhythmia remains unclear. This study is aimed at clarifying the optimal approach to this potentially life-threatening issue at the time of PVR.-A retrospective analysis was performed on 205 patients with repaired TOF undergoing PVR at our institution between 1988 and 2010. Median age was 32.9 (range 25.6 years). Previous ventricular tachycardia (VT) occurred in 16 patients (8%) and 37 (16%) had left ventricular (LV) dysfunction, defined as LV ejection fraction <50%. Surgical right ventricular outflow tract cryoablation was performed in 22 patients (10.7%). The primary outcome was a combined event including VT, out-of-hospital cardiac arrest, appropriate implantable cardioverter-defibrillator therapy and sudden cardiac death. Freedom from the combined event at 5, 10, and 15 years was 95, 90, and 79%, respectively. In the first year following PVR, 2 events occurred. Conversely, in the 22 patients who underwent surgical cryoablation, a single event occurred 7 years after PVR. A history of VT and LV dysfunction were associated with higher risk for the combined event (HR 4.7, p=0.004 and HR 0.8, p=0.02 respectively).-Patients with repaired TOF undergoing PVR with history of VT and/or LV dysfunction appear to be associated with a higher risk of arrhythmic events after operation. Events in the first year after PVR are rare, and in select high risk patients, surgical cryoablation does not appear to increase arrhythmic events and may be protective.
- Imaging Cardiac Activation Sequence during Ventricular Tachycardia in a Canine Model of Nonischemic Heart Failure. [JOURNAL ARTICLE]
- Am J Physiol Heart Circ Physiol 2014 Nov 21.:ajpheart.00196.2014.
Introduction: Noninvasive cardiac activation imaging of ventricular tachycardia (VT) is important in the clinical diagnosis and treatment of arrhythmias in heart failure (HF) patients. This study investigated the ability of the three-dimensional cardiac electrical imaging (3DCEI) technique for charactering the activation patterns of spontaneously-occurring and norepinephrine (NE) induced VTs in a newly-developed arrhythmogenic canine model of nonischemic HF. Methods: HF was induced by aortic insufficiency followed by aortic constriction in three canines. Up to 128 body-surface ECGs were measured simultaneously with bipolar recordings from up to 232 intramural sites in a closed-chest condition. Data analysis was performed on the spontaneously-occurring VTs (n=4) and the NE-induced nonsustained VTs (n=8) in HF canines. Results: Both spontaneously-occurring and NE-induced nonsustained VTs initiated by a focal mechanism primarily from the subendocardium, but occasionally from the subepicardium of left ventricle. Most focal initiation sites were located at apex, right ventricular outflow tract and left lateral wall. The NE-induced VTs were longer, more rapid, and had more focal sites than the spontaneously-occurring VTs. Good correlation was obtained between imaged activation sequence and direct measurements (averaged correlation coefficient of ~0.70 over 135 VT beats). The reconstructed initiation sites were ~10 mm from measured initiation sites, suggesting good localization in such a large animal model with cardiac size similar to human. Conclusions: Both spontaneously-occurring and NE-induced nonsustained VTs had focal initiation in this canine model of nonischemic HF. 3DCEI is feasible to image the activation sequence and help define arrhythmia mechanism of nonischemic HF-associated VTs.
- A 9-year-old boy with severe diphtherial infection and cardiac complications. [Journal Article]
- BMJ Case Rep 2014.
The incidence of diphtheria has decreased since the introduction of an effective vaccine. However, in countries with low vaccination rates it has now become a re-emerging disease. Complications from diphtheria commonly include upper airway obstruction and cardiac complications. We present a 9-year-old boy who was diagnosed with diphtheria. He presented with fever, tonsilar plaques, respiratory failure and an incomplete vaccination history. He was endotracheal intubated and received diphtheria antitoxin and penicillin on the first day of hospitalisation. He developed progressive arrhythmias and fulminant myocarditis despite early identification and treatment with equine antitoxin and antibiotics. After a temporary transvenous pacemaker insertion due to third-degree atrioventricular block and hypotension for 1 week, he developed myocardial perforation from the pacemaker tip resulting in pericardial effusion. The treatment included emergency pericardiocentesis and pacemaker removal. His electrocardiogram showed a junctional rhythm with occasional premature ventricular complexes. He then developed ventricular tachycardia and cardiac arrest and finally died.
- Catheter Ablation in Patients with Electrical Storm in Early Post Infarction Period (6 Weeks): A Single Centre Experience. [JOURNAL ARTICLE]
- Indian Pacing Electrophysiol J 2014 9; 14(5):233-239.
Electrical storm (ES) due to drug refractory ventricular tachycardia (VT) occurring within first few weeks of acute myocardial infarction (MI) has poor prognosis. Catheter ablation has been proposed for treating VT occurring late after MI, but there is limited data on catheter ablation in VT within first few weeks of MI.Five patients (4 males, mean age 54.2±12.11 years) between June 2008 to July 2012, referred for VT presenting as ES refractory to antiarrhythmic drugs in the early post infarction period (six weeks following MI) despite revascularization. Three patients had anterior wall MI and two inferior wall MI with left ventricular ejection fraction ranging from 26 to 35%.All underwent catheter ablation within 48 hours of being in VT except one who presented late. Clinical VT was induced in all five patients. Total number of VTs induced were 11 (2.2±1.09 per patient). Two patients needed epicardial ablation via pericardial puncture. Though acute success was 100%, one patient had recurrence of clinical VT the next day of procedure.One patient succumbed to sepsis with multiple organ failure. The remaining four patients are doing well without further clinical recurrence of VT over a period of 3.7 years of follow-up.Catheter ablation can be a useful adjunctive therapy for patients with recurrent VT in the early post infarction period. This procedure appears to be safe with acceptable success rate.