Spontaneous resolution of sinoatrial exit block and atrioventricular dissociation in a child with dengue fever.

Cardiac rhythm abnormalities, including ventricular arrhythmia, atrial fibrillation and atrioventricular block, have been observed during the acute stage of dengue haemorrhagic fever. Atrioventricular or complete heart block can be fatal and may require a temporary pacemaker. We report a ten-year-old girl who presented with dengue haemorrhagic fever with sinoatrial block and atrioventricular dissociation that had a spontaneous resolution.

Prevalence of interatrial block in patients with Friedreich's ataxia.

UNLABELLED: Interatrial block is a predictor of atrial arrhythmias. Aim of the present study was to estimate the prevalence of interatrial block (IAB) in Friedreich's Ataxia (FA) compared to controls and correlate it with echocardiographic and genetic features. METHODS: IAB, defined as an electrocardiographic (ECG) derived P-wave duration >120 ms, echocardiographic variables and genetic markers were evaluated in 23 FA patients with no manifestation of cardiac involvement and were compared to 23 sex- and age-matched controls. RESULTS: IAB was significantly more frequent among FA patients compared to controls (11/23 vs 1/23, p<0.005 respectively). However, no correlations with echocardiographic parameters or Guanine-Adenine-Adenine (GAA) trinucleotide repeat lengths could be established. CONCLUSION: Early recognition of IAB could allow the identification of asymptomatic FA patients who are prone to develop potentially life-threatening arrhythmias.

[Treatment of patients with long nocturnal asystoles and obstructive sleep apnea syndrome by creating continuous positive air pressure in the upper respiratory tract].

AIM: To study prevalence of obstructive sleep apnea syndrome (OSAS) in patients with nocturnal asystoles, and assess therapeutic efficiency of constant positive air pressure (CPAP) applied to upper respiratory tract in this category of patients. METHODS: The study incorporated 37 patients (33 men and 4 women, average age 50+/-11 years) with nocturnal heart beat interruptions of over 3 seconds. Baseline examination revealed grade II-III arterial hypertension in 67.5%, coronary heart disease - in 19%, diabetes mellitus in 8% and no cardiovascular disease - in 5.5% of patients. Sinus rhythm was registered in 30 (81%) of patients, 7 (19%) patients had permanent atrial fibrillation. Causes of deteriorated cardiac conduction were as follows: sinoatrial blocks and sinoatrial arrests (n=18), grade II-III atrio ventricular block (n=10), combination of these forms of bradyarrhythmias (n=2) and block of conduction to ventricles in permanent atrial fibrillation (n=7). According to intra esophageal cardiac pacing, the function of sinus node and atrio ventricular conduction appeared to be undisturbed in all patients with sinus rhythm. All patients have undergone polysomnographic (PSG) examination. For patients with OSAS, an individual selection of therapeutic pressure was carried out using the CPAP apparatuses. CPAP therapy was considered effective against OSAS if normalization of apnea/hypopnea index (AHI) was observed. RESULTS: OSAS was registered in 25 cases (68%) (mean AHI 54.9+/-28.7), 20 patients (80%) had severe grade of the syndrome. CPAP therapy appeared to be effective in all patients. At the background of treatment AHI decreased from 60.7 to 5.5 episodes per hour of sleep, mean oxygen saturation of arterial blood rose from 74 to 90%. Effect of CPAP therapy relative to cardiac conduction abnormalities was attained in all 19 patients with sinus rhythm and only in one patient with permanent atrial fibrillation. CONCLUSION: OSAS was revealed in 68% of patients with nocturnal bradyarrhythmias. Individually selected therapy with constant positive pressure in patients with nocturnal asystoles and OSAS efficiently eliminated in sleep asystoles and made it possible to avoid pacemaker implantation in some patients.

[General anesthesia with remifentanil for a patient having sinoatrial block and constrictive pulmonary disorder].

There is little report describing the effect of remifentanil on cardiac conduction system. We present a successful anesthetic management with remifentanil in a patient with sick sinus syndrome. A 66-year-old woman (31-kg, 121-cm) having sinoatrial (SA) block was diagnosed as having hepatic cell carcinoma, and radiofrequency ablation (RFA) was scheduled. She was also suffering from kyphosis due to the past history of tuberculous spondylitis. Preoperative examination of her respiratory function indicated a severe constrictive pulmonary disorder. Anesthesia was induced with propofol (30 mg), and maintained with sevoflurane (1-2%) and oxygen/air in combination with remifentanil (0.5 microg x kg(-1) x min(-1)). Temporary pacemaker was prepared during anesthesia. Neither remifentanil nor sevoflurane deteriorated SA block and her heart rate was well controlled. Respiratory dysfunction was not seen in the postoperative course. Our case suggests that remifentanil may be a suitable analgesic for patients with cardiac conduction abnormalities.

An example of combined sinoatrial and atrioventricular block.

Combined sinoatrial and atrioventricular block is rare and has been reported in patients on digitalis. We report a case of combined Mobitz type II sinoatrial block and 2:1 atrioventricular block in a patient on no medication who presented with recurrent syncope.

Dizziness and near syncope due to sinus bradycardia and sinoatrial block associated with obesity and daytime tiredness. A clear indication for pacemaker implantation?

BACKGROUND: The symptomatic sick sinus syndrome presents a classic indication for the implantation of a dual-chamber pacemaker according to the current national and international guidelines. However, in cases where dizziness and near syncope due to a sinus node dysfunction are found together with clinical characteristics of a sleep apnea-hypopnea syndrome (SAHS), screening for sleep apnea would be prudent before deciding for a pacemaker. CASE STUDY: The case report presented herein describes a patient with symptomatic sinus bradycardia and second-degree SA block with a Wenckebach periodicity, in whom the primary decision to implant a pacemaker was altered in favor of treatment with nCPAP (nasal continuous positive airway pressure) because after a careful and thorough evaluation of the patient's history and symptoms, a severe mixed SAHS was diagnosed. CONCLUSION: On diagnosing SAHS with an obstructive component in patients with symptomatic bradycardia and SA block, there is no primary need for a pacemaker, but rather for implementing treatment with nCPAP. Thus, a pacemaker should only be considered in patients with intolerance or bad compliance regarding nCPAP, or in those in whom no significant reduction of bradyarrhythmia is achieved.

Association of atrial fibrillation in patients with interatrial block over prospectively followed controls with comparable echocardiographic parameters.

Interatrial block (IAB) (P wave >or=110 ms) is a potential risk of atrial fibrillation (AF). However, few investigations have assessed the relevance of echocardiographic parameters, particularly the contribution of its known correlate, left atrial enlargement in this regard. We identified 32 consecutive patients with comparable echocardiographic parameters, such as left atrial dimension and left ventricular ejection fraction. Patients were evaluated for IAB and followed for 15 months for cardiovascular events (heart failure, transient ischemic attacks, and stroke), atrial tachyarrhythmias (AF/atrial flutter), and death. Preexisting AF and IAB (p = 0.02) were significantly associated with future AF events. However, logistic regression analysis indicated that IAB was not an independent predictor of future AF, only preexisting atrial tachyarrhythmias was (hazard ratio 39.5, 95% confidence interval 2.7 to 576.3, p = 0.007). In conclusion, in patients with comparable echocardiographic parameters, such as left atrial size and left ventricular ejection fraction, IAB remained associated with AF after a 15-month follow-up. Additional investigation is needed to confirm the extent of the association.

Limited utility of interatrial block in predicting ischemia on coronary angiography in patients with suboptimal exercise performance.

INTRODUCTION: Interatrial block (P waves > or = 110 ms) is thought to be associated with underlying myocardial ischemia during exercise but has not been extensively investigated in patients with suboptimal or borderline exercise tolerance tests (< 3 min exercise). We utilized coronary angiography to assess the relationship of both, the resting baseline and exercise induced increase in P-wave duration with coronary artery disease among patients who had undergone such tests. METHODS: We prospectively identified 51 consecutive patients with interatrial block who had coronary artery disease and hypertension but not atrioventricular valvular heart disease, and had undergone coronary angiography to evaluate myocardial ischemia after a suboptimal exercise tolerance test. A control group of 64 consecutive exercise tolerance test patients with similar preliminary characteristics but without interatrial block at rest was used for comparison. Patients from both groups were then appraised for significant obstructive lesions (> 70%) on coronary angiography that were suggestive of myocardial ischemia. RESULTS: Obstructive coronary artery lesions suggestive of myocardial ischemia were more frequent among interatrial block patients but this was not statistically significant (p=0.25). However, change in P-wave duration of > 20 ms occurred more frequently in interatrial block patients in the presence of a positive exercise tolerance test. Among patients without interatrial block at baseline, more patients who developed new interatrial block had significant disease on coronary angiography. CONCLUSION: The utility of using interatrial block toward predicting myocardial ischemia among patients with suboptimal exercise tolerance tests is limited. However, further investigation on the early change in P-wave duration in patients with interatrial block and the development of new interatrial block during exercise could be helpful in optimizing exercise tolerance tests, particularly when borderline or suboptimal.

Prospective evaluation of atrial tachyarrhythmias in patients with interatrial block.

INTRODUCTION: Interatrial block (P-wave> or =110 ms) is clinically associated with left atrial enlargement and electromechanical dysfunction as well as atrial tachyarrhythmias. We prospectively evaluated the incidence of such arrhythmias, especially atrial fibrillation among patients with interatrial block over the course of 1 year. METHODS: 118 patients (aged 48 to 104 years; female 56.6%) who had been hospitalized between December 15, 2004 and January 14, 2005 were identified and divided into 3 groups based on their respective baseline electrocardiogram (interatrial block=41 patients, sinus non-interatrial block=51 patients and atrial tachyarrhythmia=24 patients). Patients were subsequently followed for 12 months for pertinent cardiovascular events (heart failure, peripheral embolism, transient ischemic attacks and stroke), atrial tachyarrhythmias (atrial fibrillation and atrial flutter) and death as endpoints. RESULTS: 19 patients (17.9%) had atrial fibrillation during the 12-month follow-up (sinus non-interatrial block group=4 [9.1%], interatrial block group=12 [29.3%] and atrial tachyarrhythmia group=3 [14.3%]). Coronary artery disease, hypertension, pre-existing atrial fibrillation history, dilated cardiomyopathy, atrioventricular valvular disease and interatrial block (age- and sex-adjusted hazard ratio=4.2; 95% confidence interval 1.2-14.4; p=0.02) were significantly associated with future events of atrial fibrillation. However, logistic regression analysis indicated that interatrial block was not an independent predictor of future atrial fibrillation whereas only history of pre-existing atrial tachyarrhythmias was (hazard ratio=23.6; 95% confidence interval 4.5-121.7; p=0.0002). CONCLUSION: Interatrial block may be associated with atrial fibrillation but in a 12-month period, does not appear to be an independent predictor of future atrial fibrillation. Continued prospective investigation of such a relationship is certainly warranted given its already known consequences.

[Mitral valve prolapse and sudden death: a case report]. / Prolapsus valvulaire mitral et mort subite: à propos d'une observation.

Mitral valve prolapse (MVP) is a common disorder that, in general, has a good prognosis. Rare occasions of sudden death have been reported in patients with MVP and it is presumed that the basis of sudden death is arrhythmias. We report a case of a 47 years old men affected by MVP complicated by ventricular arrhythmias and sinoatrial block; who died suddenly from ventricular tachycardia. The pathophysiology and risk factors of sudden cardiac death in MVP are discussed.

Atrial escape capture bigeminy.

Atrial escape capture bigeminy is a rare electrocardiographic entity. A case of atrial escape sinus capture presenting as true atrial bigeminy is reported.