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Third-degree block [keywords]
- Syncope with atypical trunk convulsions in a patient with malignant arrhythmia. [JOURNAL ARTICLE]
- Epileptic Disord 2013 Jun 17.
Syncope is a condition often misdiagnosed as epilepsy. Syncope caused by cardiac disturbance is a life-threatening condition and accurate diagnosis is crucial for patient outcome. We present a case study of a 71-year-old woman who was referred to our epilepsy centre with a diagnosis of refractory epilepsy. We diagnosed convulsive syncope caused by malignant cardiac arrhythmia based on the presence of cardiac asystole lasting for 20-30 seconds, which was caused by sick sinus syndrome combined with third-degree atrioventricular block. The most prominent feature of this syncope was atypical trunk (abdominal or thoracoabdominal) convulsions, which were accompanied by other motor signs (head and eye deviation and brief jerks of the extremities). In the periods between attacks, all investigations, including standard 12-lead ECG and 24-hour ECG monitoring, were normal. This case study highlights the challenge in differential diagnosis of sudden loss of consciousness. [Published with video sequences].
- Accelerated junctional rhythm in children with acute rheumatic fever: is it specific to the disease? [JOURNAL ARTICLE]
- Cardiol Young 2013 May 22.:1-5.
Objective:During the course of acute rheumatic fever, some electrocardiographic changes are seen. First-degree atrioventricular block is the most common electrocardiographic abnormality. Second- and third-degree atrioventricular block, ventricular tachycardia, and junctional acceleration are also seen. In the present study, the specificity of accelerated junctional rhythm to acute rheumatic fever was investigated.
Methods:The study included patients with acute rheumatic fever (Group 1), healthy children who had suffered from recent group A β-haemolytic streptococcal upper respiratory tract infection but did not develop acute rheumatic fever (Group 2), and patients who had other diseases that may affect the joints and/or heart (Group 3).
Results:Accelerated junctional rhythm was detected in 10 patients in Group 1, but in none of the patients from Group 2 or 3. Specificity of accelerated junctional rhythm for acute rheumatic fever was 100% and the positive predictive value was 100%.
Conclusion:Accelerated junctional rhythm is specific to acute rheumatic fever. Although its frequency is low, it seems that it can be used in the differential diagnosis of acute rheumatic fever, especially in patients with isolated polyarthritis.
- Provocation of an autoimmune response to cardiac voltage-gated sodium channel NaV1.5 induces cardiac conduction defects in rats. [JOURNAL ARTICLE]
- J Am Coll Cardiol 2013 May 15.
OBJECTIVE:This study tested the hypothesis that inducing an autoimmune response against the cardiac sodium channel (NaV1.5) induces arrhythmias.
BACKGROUND:Sporadical evidence supports the concept that autoantibodies may cause cardiac arrhythmias but substantial experimental investigations using in vivo models have been lacking to date. The NaV1.5 is essential for cardiac impulse propagation and its dysfunction has been linked to conduction disease.
METHODS:Rats were immunized with a peptide sequence derived from the third extracellular loop of the first domain of NaV1.5. After 28 days, we evaluated in vivo both the electrical and mechanical parameters of cardiac function. Histopathology, myocardial gene and protein expression were assessed. Whole-cell patch-clamp was used to measure sodium current (INa) density in isolated cardiomyocytes.
RESULTS:NaV1.5-immunized rats had high titers of autoantibodies against NaV1.5. On ECG recording, NaV1.5-immunized animals showed significantly prolonged PR-intervals. During holter ECG-monitoring we observed repeated prolonged episodes of third-degree atrioventricular and sinoatrial block in every NaV1.5-immunized animal, but not in controls. Immunization had no effect on cardiac function. In comparison to controls, myocardial NaV1.5 mRNA and protein levels were decreased in immunized rats. INa density was reduced in cardiomyocytes incubated with sera from NaV1.5-immunized rats and from patients with idiopathic atrioventricular block (AVB) in comparison to sera from respective controls. In patients with idiopathic AVB, we observed autoantibodies against NaV1.5 that were absent in sera from healthy controls.
CONCLUSIONS:Provocation of an autoimmune response against NaV1.5 induces conductance defects probably caused by a reduced expression level and an inhibition of NaV1.5 by autoantibodies, resulting in decreased INa.
- Cardiologic predictors of sudden death in patients with myotonic dystrophy type 1. [Journal Article]
- J Clin Neurosci 2013 Jul; 20(7):1002-6.
The aim of this study was to analyze survival, causes of death and cardiologic predictors of sudden death in a large cohort of patients with myotonic dystrophy type 1 (DM1). The study was comprised of 171 adult DM1 patients hospitalized at the Neurology Clinic in a 20-year period. Severe electrocardiographic (ECG) abnormality included at least one of the following: rhythm other than sinus, PR interval of ⩾240ms, QRS complex duration of 120ms or more, and second-degree or third-degree atrioventricular (AV) block. Survival data were analyzed by the Kaplan-Meier test, log-rank test and Cox regression analysis. During the mean follow-up period of 9.4±5.4years, a pacemaker was implanted in 5.8% of DM1 patients and 14% of patients died. The mean age at death was 55.6±12.5years. The most common causes of death in our cohort were sudden death (41.7%) and respiratory failure (29.2%). The presence of palpitations (hazard ratio [HR]=4.7, p<0.05) and increased systolic blood pressure (HR=9.8, p<0.05) were significant predictors of sudden death. Among ECG parameters, severe ECG abnormality (HR=4.7, p<0.05), right bundle branch block (RBBB; HR=3.9, p<0.05) and bifascicular block (HR=5.8, p<0.05) were significant predictors of sudden death.
- Ventriculoatrial conduction and related pacemaker-mediated arrhythmias in patients implanted for atrioventricular block: An old problem revisited. [JOURNAL ARTICLE]
- Int J Cardiol 2013 Apr 29.
INTRODUCTION:Ventriculoatrial (VA) conduction and related pacemaker-mediated tachyarrhythmias (PMT) have not been systematically investigated in a large cohort of patients implanted for symptomatic atrioventricular (AV) block.
METHODS AND RESULTS:Two hundred fifty consecutive patients (71±14years, 63% male) implanted for symptomatic second- or third-degree AV block were screened for retrograde VA conduction and related PMTs including endless loop tachycardia (ELT) and repetitive nonreentrant VA synchrony (RNRVAS). After a mean post-implantation period of 38±12months, AV block was persistent in 137 (55%) and variable in 113 (45%) patients. Retrograde 1:1 conduction was present in 76 patients (30%) with a mean VA conduction time of 258±65ms. The incidence of VA conduction varied considerably according to the presence and type of anterograde conduction block. Retrograde conduction was present in 24 of 137 patients (18%) with persistent AV block. Fifteen of the 76 patients (20%) with VA conduction had ≥1 documented PMT. The recorded arrhythmias were ELT in 11 and RNRVAS in 4 patients. VA conduction time was significantly longer in patients with than without PMT (297±64 vs. 249±62ms, resp., P<0.01). None of the patients without VA conduction had documented PMTs.
CONCLUSIONS:Retrograde VA conduction and related PMTs are not uncommon in patients implanted for symptomatic AV block. Testing for retrograde conduction should therefore be performed in all patients with AV block in order to optimize device programming and prevent PMTs.
- Third degree atrioventricular block associated with treatment with rivastigmine transdermal patch. [Journal Article]
- J Geriatr Cardiol 2013 Mar; 10(1):113-5.
Rivastigmine transdermal patch is indicated for patients with Alzheimer's disease and dementia with Parkinson's disease. Rivastigmine, an acetylcholinesterase inhibitor, has several common adverse effects, mainly involving the gastrointestinal tract, but few cardiovascular adverse effects have been reported. This report presents two cases of patients presenting with 3(rd) degree atrioventricular block. Both patients were treated with the acetylcholinesterase inhibitor, rivastigmine. In one case, the patient reverted to normal sinus rhythm following the discontinuation of rivastigmine, and the atrioventricular block reappeared after rivastigmine was reinstated. In the other case, the atrioventricular block did not revert and the patient required a permanent pacemaker. Both bradycardia and syncope have previously been reported as adverse events in patients treated with acetylcholinesterase inhibitors. However, the type of bradycardia and the etiology of the syncope are rarely specified. Rivastigmine, and other acetylcholinesterase inhibitors, are widely used in the pharmacological treatment of Alzheimeŕs disease. We recommend that physicians are vigilant of possible warning signs, such as dizziness, syncope and bradycardia.
- Results of simplified single-patch repair for complete atrioventricular septal defect. [Journal Article]
- Arq Bras Cardiol 2013 Mar; 100(3):288-93.
Since Wilcox's description of the simplified single-patch technique for atrioventricular septal defect (AVSD) repair in 1997, several studies have compared that technique with the two-patch technique.To report the mid- and long-term results of the simplified single-patch technique for complete AVSD repair.Retrospective study of 16 consecutive cases between January 2001 and December 2011. The patients' mean age was 18.31 ± 34.19 months (2 months - 11 years), and their mean weight, 7.80 ± 6.12 kg (3.77 - 25.0 kg). Six patients were males and 14 had Down syndrome. Mean follow-up duration was 54.97 ± 47.79 months.Mean cardiopulmonary bypass time was 74.63 ± 18.48 min (49 - 112 min), and mean aortic cross-clamp time, 46.44 ± 11.89 min (34 - 67 min). Two patients died during hospitalization (12.5%), both of cardiovascular causes. Three patients underwent reoperation due to left atrioventricular (AV) valve regurgitation, and two had third-degree VA block, requiring permanent pacemaker implantation. No patient had left ventricular outflow tract obstruction. The 14 surviving patients remain asymptomatic, ten of whom with mild left VA valve regurgitation (71.42%).The simplified single-patch technique for complete AVSD repair proved to be feasible, providing adequate correction of the defects and favorable clinical and echocardiographic outcome in the mean 57.97-month follow-up.
- Clinical impact of the implantable loop recorder in patients with isolated syncope, bundle branch block and negative workup: a randomized multicentre prospective study. [Journal Article, Research Support, Non-U.S. Gov't]
- Arch Cardiovasc Dis 2013 Mar; 106(3):146-54.
Few studies have compared conventional testing with prolonged monitoring using an implantable loop recorder (ILR) following the first syncope episode in patients with bundle branch block (BBB) and negative workup.To compare two syncope evaluation strategies-primary use of an ILR (Group 1) versus conventional testing (Group 2)-and to estimate the prevalence of significant arrhythmias in the ILR patient subset.From January 2005 to December 2010, 78 patients admitted after one syncope episode were randomized to ILR (n=41) or conventional follow-up (n=37). Mean follow-up was 27 ± 12 months.Mean age was 76 ± 8 years and 30 patients were women (38.5%); 18 presented cardiomyopathy (23%) and 12 had a history of atrial fibrillation (15.4%). Mean left ventricular ejection fraction was 56.5 ± 11% and mean His-to-ventricle interval was 55 ± 6ms based on negative electrophysiological study (EPS). Electrocardiogram abnormalities involved: 34 left bundle branch blocks (BBBs); 11 right BBBs; and 33 bifascicular blocks. Overall, 21 patients (27%) developed significant arrhythmic events: ventricular tachycardia (n=1; 1.3%); sudden death (n=2; 2.6%); third-degree atrioventricular (AV) block (n=14; 18%); sick sinus syndrome (n=4; 5.1%). In 19 (24.4%) patients, relevant arrhythmias were detected, with a significant difference between the ILR group (n=15/41; 36.6%) and the conventional follow-up group (n=4/37; 10.8%) (P=0.02). Eighteen patients were implanted with pacemakers; one received an implantable defibrillator. No predictors of AV block were identified in the ILR group.In this randomized prospective study, the ILR strategy proved largely superior to conventional follow-up in detecting recurrent events, with a potential impact on therapeutic management. This observation highlights the usefulness of early monitoring in patients with BBB and negative EPS even after the first syncope episode but an empiric pacemaker strategy remains to be validated in this selected population.
- Acute hyperglycaemia and inflammation in patients with ST segment elevation myocardial infarction. [Journal Article]
- Kardiol Pol 2013; 71(3):260-7.
Acute hyperglycaemia in patients with acute coronary syndromes (ACS) is associated with increased cardiovascular (CV) risk among both diabetic and non-diabetic patients although the mechanisms underlying this association are not clearly understood. Acute hyperglycaemia in patients with ACS may be associated with increased systemic inflammation. Leukocytes are the major cellular mediators of inflammation and their elevated count is associated with higher CV event rate in ACS patients. Thus, it is possible that there is a relationship between acute hyperglycaemia and high leukocyte count and concomitant presence of these two conditions may contribute to increased CV risk among patients with ST segment elevation myocardial infarction (STEMI).To investigate the relationship between acute hyperglycaemia and high leukocyte count and to evaluate its association with outcomes in patients with STEMI.Glucose level and leukocyte count on admission were measured in 246 patients with STEMI admitted in 2004- -2007 to the First Department of Cardiology and Hypertension at the University Hospital in Cracow who were treated with an early invasive management strategy. Patients were divided into two groups, with acute hyperglycaemia (glycaemia on admission ≥ 7.8 mmol/L) and with normoglycaemia (glycaemia on admission < 7.8 mmol/L). Leukocyte count was defined as high when it was greater than or equal to the median in the overall study group.Acute hyperglycaemia was noted in 136 (55.3%) patients. Median leukocyte count on admission in the overall study group was 10.8 × 103/mm3 (interquartile range: 8.5-13.0). Significantly higher in-hospital mortality (11.8% vs. 1.8%, p = 0.0029) and higher rates of cardiogenic shock (10.3% vs. 0.9%, p = 0.0022), Killip class > 1 heart failure (HF; 44.1% vs. 20.0%, p < 0.0001), atrial fibrillation (11.0% vs. 3.6%, p = 0.0308), ventricular fibrillation (5.9% vs. 0.9%, p = 0.0389), repeated percutaneous coronary angioplasty (5.2% vs. 0.0%, p = 0.0158), the primary endpoint defined as death and/or cardiogenic shock (16.9% vs. 1.8%, p = 0.0001), and the secondary endpoint defined as atrial fibrillation and/or second or third degree atrioventricular block and/or HF and/or stroke/transient ischaemic attack (53.7% vs. 23.6%, p < 0.0001) were noted in the acute hyperglycaemia group in comparison with the normoglycaemic group. Adverse events were associated with high leukocyte count in all patients and in both diabetic and non-diabetic subgroups. Mean leukocyte count was higher in patients who died (13.3 ± 4.01 vs. 11.0 ± 3.56 [103/mm3], p = 0.0115; 14.2 ± 1.59 vs. 10.8 ± 3.18 [103/mm3], p = 0.0210; and 13.5 ± 4.79 vs. 11.1 ± 3.72 [103/mm3], p = 0.0363 in the overall study group, diabetics and non-- diabetics, respectively), in patients with cardiogenic shock (14.0 ± 4.56 vs. 11.0 ± 3.52 [103/mm3], p = 0.0019; and 15.4 ± 4.93 vs. 11.0 ± 3.66 [103/mm3], p = 0.0007 in the overall study group and non-diabetics, respectively), and in patients with HF (12.1 ± 3.78 vs. 10.8 ± 3.51 [103/mm3], p = 0.0083; and 12.1 ± 3.39 vs. 10.3 ± 2.90 [103/mm3], p = 0.0159 in the overall study group and diabetics, respectively) as compared to patients without respective adverse events. Glucose level on admission correlated positively with the on-admission leukocyte count. This correlation was statistically significant in the overall study group (r = 0.25, p < 0.0001), in diabetics (r = 0.27, p = 0.021), and in non-diabetics (r = 0.35, p < 0.0001). Patients with both acute hyperglycaemia and the leukocyte count greater than or equal to the median in the overall study group had a higher in-hospital risk of death and/or cardiogenic shock (odds ratio 17.6, 95% CI 1.9-165.3, p = 0.0122).Acute hyperglycaemia is associated with worse in-hospital outcomes in patients with STEMI. More severe inflammation (defined as leukocyte count on admission) is noted in STEMI patients with adverse events. A significant positive correlation can be seen between glucose level and leukocyte count on admission, and concomitant presence of both acute hyperglycaemia and more severe inflammation in patients with STEMI was found to be an independent predictor of poor in-hospital outcomes.
- Enigmatic rhythm: swift action is key in complex cardiac case. [Journal Article]
- JEMS 2012 Dec; 37(12):26-7.
This was an interesting, yet enigmatic, case. An elderly male with a prolonged QT interval developed a third-degree block with a slow ventricular rate. This spontaneously converted to a polymorphic v tach (probably torsades) that worsened his cardiac output causing pulmonary congestion and hypoxia. He ultimately converted back to a third-degree block following treatment with amiodarone and magnesium sulfate. More importantly, paramedics recognized the complexity of the case and, because of the very short transport time, elected to rapidly transport the patient. Complex cases such as this do not fit into any standardized EMS protocol. Because of this, we need paramedics who see and recognize serious conditions that don't fall within the constraints of algorithmic protocols. In this case, they identified the problem, transported promptly and alerted the staffin a busy ED of the patient's complex and deteriorating condition.