Intermittent Complete Atrioventricular Block Research Articles

Lyme carditis: Early occurrence and prolonged recovery

Lyme carditis is an uncommon manifestation of early disseminated Lyme disease. This case illustrates a 66-year-old male with complaints of fatigue, myalgias, and fever after a tick bite 3days earlier. A large erythema migrans was found on the chest wall. Initial electrocardiogram showed sinus rhythm with second degree 2:1 atrioventricular (AV) block, which progressed to intermittent complete AV block rapidly. He was treated with intravenous ceftriaxone. Over the course of 2-weeks of antibiotic therapy, the intermittent high-grade AV block improved slowly and progressively. This case highlights the importance of timely diagnosis and appropriate management to achieve a favorable prognosis.

Isolated cardiac sarcoidosis diagnosed by electroanatomic voltage mapping-guided endomyocardial biopsy combined with magnetic resonance imaging and positron emission tomography

Cardiac involvement in sarcoidosis is related to lethal arrhythmias and is considered a serious condition. Because steroid therapy is an effective treatment, early diagnosis of cardiac sarcoidosis (CS) is of paramount importance in respect to improving prognosis. However, the diagnostic yield of histologic examination by endomyocardial biopsy (EMB) in CS is usually low. We report the case of isolated CS histopathologically proven by electroanatomical voltage mapping (EVM)-guided EMB combined with cardiac magnetic resonance imaging (CMR) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). A 53-year-old man presented with general fatigue. Electrocardiography showed intermittent complete atrioventricular block and echocardiography showed reduced cardiac function. CMR showed late gadolinium enhancement (LGE) in the areas of myocardium with suspected sarcoidosis. Next, we performed an EVM-guided EMB and found a non-caseating epithelioid granuloma in the right ventricular septum, which showed low voltage on EVM and LGE on CMR. FDG-PET showed accumulation in the same cardiac region. This case shows that EVM-guided EMB combined with diagnostic imaging can be a valuable approach in cases of suspected isolated CS.<Learning objective: To reduce inflammation and prevent ventricular remodeling by early corticosteroid treatment, detecting cardiac sarcoidosis (CS)-affected regions is important. Cardiac magnetic resonance imaging and positron emission tomography help detect such regions. However, histopathological diagnosis of CS by endomyocardial biopsy (EMB) is usually difficult. The present case suggests that electroanatomical voltage mapping-guided EMB combined with diagnostic imaging improves detection of CS-affected regions.>

Echocardiographic Guided Closure of Perimembranous Ventricular Septal Defects

Transesophageal echocardiogram-guided minimally invasive periventricular device closure of perimembranous ventricular septal defects (pmVSDs) without cardiopulmonary bypass is a treatment option for pmVSDs. We introduce our improvements to this technique and mid-term follow-up results. From May 2011 to May 2014, 187 patients with pmVSDs aged 6 months to 31 years (8.2 ± 10.2 years) were enrolled in this study. The procedure was performed through a new transthoracic approach of 1 to 2 cm without sternotomy. Device selection and the operative procedure were monitored by transesophageal echocardiogram. The patients underwent follow-up examinations of echocardiography and electrocardiogram at 1 month, 3 months, 6 months, and 1 year after the operation and annually thereafter. The defects were closed successfully in 179 patients (95.7%), and in 8 patients the operation was converted to conventional surgical repair. Six patients (3.4%) had an incomplete right bundle branch block. One patient experienced an intermittent complete atrioventricular block on the fourth day after the operation, and sinus rhythm was restored by corticosteroid therapy after 5 days. A trivial residual shunt was observed in 8 patients (4.5%) during the procedure. The average hospital stay was 3.1 ± 0.9 days. Follow-up in all patients ranged from 1 month to 36 months (median, 12.6 months), and aortic regurgitation, malignant arrhythmia, and device dislocation were not observed in any patients. However, 3 patients (1.7%) still had a trivial residual shunt at their last follow-up. Periventricular device closure through a modified transthoracic approach without sternotomy is a potentially safe and effective treatment option for pmVSDs. Controlled studies with long-term follow-up are necessary.

Prevalence of preoperative arrhythmias in children with delayed treatment of severe congenital heart disease

Aim — Our aim was to determine the real importance of rhythm and conduction disorders in children with unoperated severe congenital heart disease.Methods — Consecutive children with delayed treatment of severe congenital heart disease were prospectively studied for the occurrence of arrhythmias before any invasive investigation or surgical procedure was performed.Results — All 168 children were in sinus rhythm. One hundred and fifty-eight patients (94%) had no significant preoperative findings. One child with double discordance had an intermittent complete atrioventricular block, and another one had a long QT syndrome. Children with severe ventricular dysfunction had paroxysmal atrioventricular re-entry tachycardia in 3 cases and abnormally frequent premature ventricular complexes in 3 other cases. Children with severe left atrial dilatation had periods of atrial ectopic tachycardia in one case and atrial fibrillation in another case.Conclusions — The prevalence of rhythm and conduction disorders is relatively low in children with delayed treatment of severe congenital heart disease. Only those with congenital heart disease classically combined with such disorders and those with prolonged severe ventricular dysfunction and/or atrial dilatation are at risk of developing significant arrhythmias and should undergo a preoperative assessment of arrhythmias.

Swallow Syncope Associated with Complete Atrioventricular Block in an Adolescent

We describe a 16-year-old female with a history of swallowing-induced syncope. The physical examination, ECG, echocardiography, barium swallow test, and thyroid function tests were within normal limits. The ambulatory ECG revealed intermittent complete atrioventricular block only associated with swallowing. There was also intermittent first-degree atrioventricular block not related to eating. An electrophysiologic study was performed during the implantation of a single-chamber transvenous ventricular pacemaker. There was mild atrioventricular nodal conduction disturbance with a His-ventricular interval of 70 msec and Wenckebach cycle length of 420 msec. During 1 year follow-up, the patient remained asymptomatic.

Intermittent Complete Atrioventricular Block after Long Term Low-Dose Carbamazepine Therapy with a Serum Concentration Less than the Therapeutic Level

After twelve months of low dose carbamazepine therapy (200 mg daily) for temporal lobe epilepsy, a 66-year-old woman presented to the hospital complaining of frequent episodes of sudden dizziness. Because Holter monitoring documented intermittent complete atrioventricular block, the patient was admitted to the hospital when the serum concentration of carbamazepine was 4 microg/mL. After discontinuation of carbamazepine, the patient returned to normal sinus rhythm. The present case suggests that complete atrioventricular block may occur long after initiation of carbamazepine therapy in an older woman even if the daily dosage or the serum concentration of carbamazepine is low.

AHA/ACCF Scientific Statement on the Evaluation of Syncope

AHA/ACCF Scientific Statement on the Evaluation of Syncope

Chronic bifascicular block with intermittent complete atrioventricular block induced by hyperthyroidism

a Department of Internal Medicine, Department of Medicine, Taipei Medical University School of Medicine and Taipei Wan-Fang Hospital, Taiwan, R.O.C. b Division of Endocrinology and Metabolism, Department of Medicine, Taipei Medical University School of Medicine and Taipei Wan-Fang Hospital, Taiwan, R.O.C. c Division of Cardiovascular Medicine, Department of Medicine, Taipei Medical University School of Medicine and Taipei Wan-Fang Hospital, Taiwan, R.O.C. d Institute of Clinical Medicine, Yang-Ming University School of Medicine, Taiwan, R.O.C.

Atrial tachyarrhythmias and permanent pacing after pediatric heart transplantation

Background: Atrial tachyarrhythmias have been reported in as high as 50% of adult heart recipients. Limited information is available on arrhythmias in pediatric transplant patients. Our objective was to determine the prevalence and significance of atrial tachyarrhythmias and permanent pacing following pediatric heart transplantation. Methods: A retrospective review of the medical records, electrocardiograms, and Holter recordings of all consecutive patients following heart transplantation at Children’s Hospital, Boston ( n = 104) and Lucile Packard Children’s Hospital, Stanford ( n = 123) was performed. The study group consisted of 227 patients with a median age at transplant of 10.2 yrs (1 day–23.3 yrs). Results: Atrial tachyarrhythmias occurred in 32 patients (14%) at a median of 15 days post-transplant (1 day–9.2 yrs) and included atrial flutter ( n = 13), atrial fibrillation ( n = 7), ectopic atrial tachycardia ( n = 5), atrioventricular reciprocating tachycardia or atrioventricular node reentry ( n = 5), and other ( n = 2). Atrial flutter was the only tachyarrhythmia associated with allograft rejection (6/13 atrial flutter vs. 0/7 atrial fibrillation vs. 0/5 ectopic atrial tachycardia, p = 0.03). Patients with atrial fibrillation had a 2.5 fold (95%CI 1.7–3.5) higher risk of death or retransplant compared to patients without atrial fibrillation. Ectopic atrial tachycardia tended to occur in younger recipients compared to atrial fibrillation and flutter (2.7 yrs vs 18.6 yrs and 8.5 yrs respectively, p = 0.06) and was associated with a benign clinical course. There was no association between atrial tachyarrhythmias and graft ischemic time, surgical technique, or coronary artery disease. Pacemakers were required in 12 patients (5.2%), 7 with sinus node dysfunction and 5 for intermittent complete atrioventricular block. There was no consistent association between the need for permanent pacing and coronary artery disease, rejection, or surgical technique. Conclusions: Atrial tachyarrhythmias and permanent pacing were uncommon in this cohort of pediatric heart transplant recipients. Association with cardiac rejection, clinical course, and mortality varied depending on the tachyarrhythmia mechanism.

Cardiac arrhythmias mimicking primary neurological disorders: a difficult diagnostic situation.

Cardiac arrhythmias can present with the signs and symptoms of a seizure disorder. This potentially life-threatening underlying cause of non-febrile seizures should be recognized early, since successful specific treatment is possible. The purpose of this retrospective study was to examine common features in such patients. Over a period of 25 years, eight patients were initially treated for up to 5 years at our institution for a seizure disorder until dysrhythmia as the underlying cause of the seizures was disclosed. The main symptom was drop attacks coinciding with physical activity or emotional stress. Convulsions were only rarely observed. In five of the eight patients the underlying disorder was the long-QT-syndrome (Romano-Ward syndrome). In one patient intermittent complete atrioventricular block was found, another patient showed ventricular tachydysrhythmia of unknown etiology and the last patient suffered from hypertrophic cardiomyopathy.

Complete heart block as a cause of syncope in hypertrocphic cardiomyopathy

SummaryWe report a 12-year-old boy with hypertrophic cardiomyopathy presenting with syncope. His electrocardiogram showed first-degree atrioventricular block, complete right bundle branch block, conduction delay in the anterior fascicle of the left bundle branch, and intermittent complete atrioventricular block. We detected hypertrophic cardiomyopathy in the mother. The relationship between the diseases is discussed, and interpreted in the light of previous descriptions.