Cardiac involvement in acute Q fever is rare. We report 2 cases of an advanced atrioventricular block in young adult patients in Israel who sought care for acute Q fever without evidence of ...myocarditis. Q fever should be suspected in unexplained conduction abnormalities, especially in febrile young patients residing in disease-endemic areas.
Congenital long QT syndrome (LQTS) is a cardiac channelopathy that leads to the prolongation of the QT interval. This prolongation can lead to ventricular tachyarrhythmia, syncope, and sudden cardiac ...death. There are various types of LQTS. Treatment of LQT1 and LQT2 is mainly based on antiadrenergic therapy. LQT3, on the other hand, is a result of a mutation of the SCN5A gene, which encodes the sodium channels. In this type, patients are sensitive to vagal stimuli and episodes tend to occur at rest. Sodium channel blocking compounds, such as ranolazine, mexiletine, and flecainide, have been found to be effective in selective mutations.In this case report, we report the case of a child with congenital LQT3 (V411M) who presented first with sudden cardiac death and three weeks later with an implantable cardioverter defibrillator storm. Knowing the specific mutation and understanding the mechanism at the molecular level through an in vitro study yielded a clinically meaningful result. The patient's arrhythmia burden was totally eliminated following successful treatment with flecainide.
Background
Determining the pathogenesis of sudden cardiac arrest (SCA) in children is crucial for its management and prognosis. Our aim is to analyze the role of broad genetic testing in the ...prevention, diagnosis, and prognosis of SCA in Children.
Methods
ECG, 12‐lead holter, exercise testing, cardiac imaging, familial study, and genetic testing were used to study 29 families, in whom a child experienced SCA.
Results
After a thorough clinical and genetic evaluation a positive diagnosis was reached in 24/29 (83%) families. Inherited channelopathies (long QT syndrome and catecholaminergic polymorphic ventricular tachycardia) were the most prevalent 20/29 (69%) diagnosis, followed by cardiomyopathy 3/29 (10%). Broad genetic testing was positive in 17/24 (71%) cases. Using the Mann–Whitney test, we found that genetic testing (effect size = 0.625, p = 0.003), ECG (effect size = 0.61, p = 0.009), and exercise test (effect size = 0.63, p = 0.047) had the highest yield in reaching the final diagnosis. Genetic testing was the only positive test available for five (17%) families. Among 155 family members evaluated through cascade screening, 73 (47%) had a positive clinical evaluation and 64 (41%) carried a pathologic mutation. During 6 ± 4.8 years of follow‐up, 58% of the survived children experienced an arrhythmic event. Of nine family members who had an ICD implant for primary prevention, four experienced appropriate ICD shock.
Conclusions
The major causes of SCA among children are genetic etiology, and genetic testing has a high yield. Family screening has an additional role in both the diagnosis and preventing of SCA.
ECG, 12 lead holter, exercise testing, echocardiography, familial study, and genetic testing were used to study 29 families, in whom a child experienced sudden cardiac death or sudden cardiac arrest. LQT: long QT syndrome, CPVT: catecholaminergic polymorphic ventricular tachycardia, CM cardiomyopathy.
Calsequestrin-associated catecholaminergic polymorphic ventricular tachycardia (CPVT2) can cause sudden death in young individuals in response to stress. Beta-blockers are the mainstay medical ...treatment for patients with CPVT2. However, they do not prevent syncope and sudden death in all patients. Flecainide was reported to reduce exercise-induced ventricular arrhythmias (EIVA) in patients with ryanodine receptor-associated CPVT. The role of flecainide in CPVT2 is not known.
To summarize our experience in combining flecainide and beta-blockers in high-risk patients with CPVT2.
All patients with CPVT2 (10 patients) who have high-risk features (syncope, EIVA, or appropriate implantable cardioverter-defibrillator ICD shocks) despite beta-blockers with or without calcium channel blockers were treated with a combination of flecainide and beta-blockers. Exercise test was done before and after beginning treatment with flecainide.
All patients had EIVA and 4 had appropriate ICD shocks before flecainide treatment. EIVA-included frequent ventricular premature beats and or ventricular tachycardia during the exercise test while on high dose of beta-blockers with or without calcium channel blockers before treatment with flecainide. After combination therapy with flecainide and beta-blockers, EIVA were suppressed completely in all patients. During follow-up of 15.5 ± 10.4 months (range 2-29 months), 8 patients were free of symptoms and free of arrhythmias. Two patients had 1 VT storm episode with recurrent ICD shocks despite repeated normal stress test.
Flecainide can completely prevent ventricular arrhythmia during exercise and partially prevent recurrent ICD shocks in high-risk patients with CPVT2.
Increase of cardiac troponins occurs in a variety of clinical situations in the absence of an acute coronary syndrome (ACS). Few data exist regarding the incidence, clinical characteristics, and ...predictive value of various cardiac diagnostic tests and outcome of patients with a non-ACS–related troponin increase. We studied 883 consecutive hospitalized patients with increased cardiac troponin I levels. The discharge diagnosis was reclassified and troponin increase attributed to ACS or another process. Clinical data and results of cardiac diagnostic tests were collected. Patients were followed for a median of 30 months. Three hundred eleven patients were classified as having a non-ACS–related troponin increase (35.2%). An alternative explanation for troponin increase was found in 99% of these patients. Troponin level had poor accuracy in discriminating patients with and without ACS (area under the receiver operating characteristics curve 0.63). Coronary angiography was frequently unhelpful in excluding a non-ACS–related troponin increase because 77% of patients in the non-ACS group had significant flow-limiting coronary artery disease. Patients with non-ACS–related troponin increase had significantly higher in-hospital (hazard ratio 2.8, 95% confidence interval 2.0 to 3.8) and long-term (hazard ratio 2.0, 95% confidence interval 1.6 to 2.5) mortalities compared with patients with ACS. In conclusion, cardiac troponin level is frequently increased in hospitalized patients in the absence of an ACS and portends poor short- and long-term outcomes. Most of these patients have an alternative explanation for cardiac troponin increase. Cardiac diagnostic procedures are frequently unhelpful in excluding a non-ACS–related troponin increase.
Divergent views remain regarding the safety of treating anemia with red blood cell (RBC) transfusion in patients with acute coronary syndrome (ACS). We used a prospective database to study effect of ...RBC transfusion in patients with acute myocardial infarction (MI; n = 2,358). Cox regression models were used to determine the association between RBC transfusion and 6-month outcomes, incorporating transfusion as a time-dependent variable. The models adjusted for baseline variables, propensity for transfusion, and nadir hemoglobin previous to the transfusion. One hundred ninety-two patients (8.1%) received RBC transfusion. Six-month mortality rates were higher in patients receiving transfusion (28.1% vs 11.7%, p <0.0001). The adjusted hazard ratio (HR) for mortality was 1.9 in transfused patients (95% confidence interval CI 1.3 to 2.9). Interaction between RBC transfusion and nadir hemoglobin with respect to mortality (p = 0.004) was significant. Stratified analyses showed a protective effect of transfusion in patients with nadir hemoglobin ≤8 g/dL (adjusted HR 0.13, 95% CI 0.03 to 0.65, p = 0.013). By contrast, transfusion was associated with increased mortality in patients with nadir hemoglobin >8 g/dL (adjusted HR 2.2, 95% CI 1.5 to 3.3; p <0.0001). Similar results were obtained for the composite end point of death/MI/heart failure (p for interaction = 0.04). In conclusion, RBC transfusion in patients with acute MI and hemoglobin ≤8 g/dL may be appropriate. The increased mortality observed in transfused patients with nadir hemoglobin above 8 g/dL underscores the clinical difficulty of balancing risks and benefits of RBC transfusion in the setting of ACS.
Sleep-disordered breathing (SDB) has been associated with various benign cardiac arrhythmias occurring during sleep.
The purpose of this study was to demonstrate that SDB contributes to the ...development of life-threatening ventricular arrhythmias in patients with an established arrhythmic substrate.
We prospectively studied the association between SDB and timing of life-threatening ventricular arrhythmic events in 45 patients with an implantable cardioverter-defibrillator (ICD). SDB was defined as an apnea-hypopnea index (AHI) >10 events/hour based on an overnight sleep study. The primary outcome measure was appropriate ICD therapy, defined as antitachycardia pacing or shock for ventricular tachycardia or ventricular fibrillation during 1-year follow-up.
SDB was present in 26 (57.8%) patients. Appropriate ICD therapies were higher among patients with SDB (73% vs 47%, P = .02). Logistic regression identified SDB as a predictor of any appropriate ICD therapy (odds ratio 4.4, 95% confidence interval 1.4-15.3, P = .01). The risk for ventricular arrhythmias was higher in patients with SDB solely due to an increase in events occurring between midnight and 6 AM (odds ratio 5.6, 95% confidence interval 2.0-15.6, P = .001) with no discernible effect on appropriate ICD therapy during nonsleeping hours (odds ratio 0.7, 95% confidence interval 0.2-2.3, P = .61).
Patients with an ICD and SDB have a striking increase in the onset of life-threatening ventricular arrhythmic events during sleeping hours. These findings provide a rationale for SDB screening in patients with appropriate ICD therapy if device interrogation reveals a predominance of nocturnal onset of arrhythmias.
Sarcoidosis is a systemic granulomatous disease of unknown etiology that involves many organs and has different clinical manifestation. We reviewed the clinical manifestations of sarcoid liver ...disease. Liver involvement in sarcoidosis can be serious and life‐threatening, independent of its lung and other organ involvement.
The D1790G mutation was found in all 24 patients of an extended long QT family but not in 200 chromosomes carried by healthy individuals. We describe a 37-year-old man presenting with a typical ...spontaneous type 1 Brugada pattern who in electrophysiological testing had easily inducible ventricular fibrillation. At the age of 47 years he had an atrial ventricular type 2 block documented by an exercise test and a Holter monitor. Genetic analysis revealed a known D1790G mutation in the gene encoding of the sodium channel (SCN5A) that until now has been associated only with the long QT phenotype. Although this mutation has not been associated with a reduction of sodium channel expression, we hypothesize that sodium currents are further diminished due to the 20-mV shift of the steady-state inactivation curve, and this could contribute to the Brugada phenotype. This case is important as it allows a better understanding of the underlying molecular mechanisms of Brugada syndrome. Moreover, this observation raises concern about the safety of class IC drug therapy in long QT type 3 patients and quinidine therapy in Brugada patients, and emphasizes the importance of a thorough clinical and genetic evaluation.
AIM:To investigate the impact of using computed tomography(CT) and contact force(CF) technology on recurrence of atrial tachyarrhythmia after atrial fibrillation(AF) ablation.METHODS: This ...non-randomized study included 2 groups of patients. All patients had symptomatic recurrent paroxysmal or persistent AF and were treated with at least 1 anti arrhythmic medication or intolerant to medication. The first group included 33 patients who underwent circumferential pulmonary veins isolation(PVI) for AF during 2012 and 2013 guided by CT image integration(Cartomerge, Biosense Webster, Diamond Bar, CA, United States) of left atrium and pulmonary veins into an electroanatomic mapping(EAM) system(CT group) using standard irrigated radiofrequency catheter(Thermo Cool, Carto, Biosense Webster, Diamond Bar, CA, United States) or irrigated catheter with integrated CF sensor(Smart Touch, Carto, Biosense Webster, Diamond Bar, CA, United States). The second group included immediately preceding 32 patients who had circumferential PVI by standard irrigated catheter(Thermo Cool) using only EAM(Carto) system(EAM group). Linear lesions were performed according to the discretion of operator. RESULTS: Sex, age, and persistent AF were not different between groups. PVI was achieved in all patients in both groups. Linear ablations including cavo-tricuspid isthmus and or roof line ablation were not different between groups. Free of atrial tachyarrhythmia during follow-up of 24 mo was significantly higher among CT group compared to EAM group(81% vs 55%; respectively; P = 0.027). When 11 patients from CT group who had ablation using Smart Touch catheter were excluded, the difference between CT group and EAM became non significant(73% vs 55%; respectively; P = 0.16). Sub analysis of CT group showed that patients who had ablation using Smart Touch catheter tend to be more free of atrial tachyarrhythmia compared to patients who had ablation using standard irrigated catheter during follow-up(100% vs 73%; respectively; P = 0.07). Major complications(pericardial effusion, cerebrovascular accident/transient ischemic attack, vascular access injury requiring intervention) did not occurred in both groups.CONCLUSION:These preliminary results suggest that CT image integration and CF technology may reduce the recurrence of atrial tachyarrhythmia after catheter ablation for AF.
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