Uric acid elevation in atrial fibrillation.

INTRODUCTION: Uric acid is a cardiovascular risk marker associated with oxidative stress and inflammation. Recently, atrial fibrillation (AF) has been associated with inflammation and oxidative stress. We therefore investigated the association between AF and uric acid levels. METHODS: Consecutive patients with AF and healthy control subjects were screened. Demographic, clinical, and echocardiographic characteristics were carefully recorded. In each participant, uric acid levels and conventional inflammatory markers were determined. The final study population consisted of 45 patients with paroxysmal AF, 41 patients with permanent AF, and 48 control subjects. RESULTS: A significant variance in uric acid levels was evident between patients with paroxysmal AF (5.7 +/- 1.1 mg/dl), permanent AF (6.7 +/- 1.4 mg/dl), and control subjects (5.1 +/- 1.3 mg/dl) (p<0.001). After univariate analysis considering 2 groups (control, AF patients), the following variables were significantly associated with the presence of AF: age, hypertension, -blocker use, low left ventricular ejection fraction (LVEF), increased left atrial diameter, uric acid levels, and C-reactive protein (CRP) levels. After multivariate logistic regression analysis, only CRP was an independent predictor for AF (odds ratio, OR: 2.172). In a subgroup analysis, CRP (OR: 1.434) and LVEF (OR: 0.361) were independent predictors of paroxysmal AF, while CRP (OR: 3.048), uric acid (OR: 2.172), and LVEF (OR: 0.34) were predictors of permanent AF. CONCLUSIONS: There is an association between increased levels of uric acid and permanent AF. Also, uric acid elevation may be related to the burden of AF. Undoubtedly, larger studies should further examine this potential association.

Sensitivity and specificity of sodium channel blocking test in the diagnosis of Brugada syndrome.

The ECG features of Brugada syndrome are dynamic and frequently concealed. Sodium channels blockers are widely used to unmask the Brugada electrocardiographic (ECG) pattern. The sensitivity and specificity of I(Na) channel blocking test varies significantly. A negative I(Na) blocking test does not exclude the presence of a SCN5A mutation, which is responsible for the phenotype of Brugada syndrome. Herein, we describe the case of a 65-years-old asymptomatic male who underwent a I(Na) channel blocking test, seven years ago due to a type 2 ECG pattern (saddleback configuration) which failed to induce the diagnostic type 1 ECG pattern. Diagnostic considerations at a molecular level and their clinical relevance are being discussed.

Potential-guided versus anatomic-guided approach for slow pathway ablation of the common type atrioventricular nodal reentry tachycardia: a randomized study.

OBJECTIVE: The present study aimed to compare the effectiveness and safety of the potential- and the anatomic-guided approach for slow pathway ablation in patients with recurrent episodes of symptomatic common type atrioventricular (AV) nodal reentrant tachycardia. METHODS: Two hundred and twenty-eight patients were randomly assigned to undergo either a potential- (n=114, 47% men, mean age 52.85 +/- 14.04 years) or an anatomic-guided approach (n=114, 50% men, mean age 52.45 +/- 14.46 years) for radiofrequency ablation of the slow pathway.The mean duration of the follow-up period was 26.7 +/- 7.9 and 24.8 +/- 7.6 months in the potential- and anatomic- guided approach, respectively (P > 0.05). RESULTS: The success rate for slow pathway ablation was 100% in both ablative methods.The mean duration of atrial electrograms at the successful ablation sites of the potential- and the anatomic-guided approaches was 69 +/- 14 msec and 57 +/- 10 msec, respectively (P = 0.001).There were no significant differences between the potential- and the anatomic-guided approach regarding the duration of the procedure (121.13 +/- 56.83 vs. 109.93 +/- 57.12 min, P = 0.139), the duration of fluoroscopic exposure (6.12 +/- 3.32 vs. 6.64 +/- 3.33 min, P = 0.239) or the mean number of radiofrequency applications delivered (3.96 +/- 2.77 vs. 4.33 +/- 2.73, P = 0.311). Residual dual AV nodal pathway following successful ablation was observed in 9.6% of patients who underwent the potential-guided approach and in 23.7% of patients who underwent the anatomic method (P = 0.004). During followup, arrhythmia recurrence was observed in four patients (1.8%), two in each group (P > 0.05). CONCLUSIONS: The efficacy and safety of the slow pathway ablation is very high using either the potential- or the anatomic-guided approach.

Wide QRS complex supraventricular tachycardia with negative precordial concordance.

The authors describe the case of a 49-year-old man who experienced an episode of palpitations and dizziness. The results of 24-hour Holter monitoring demonstrated an episode of wide QRS complex regular tachycardia. During the electrophysiological study, a wide QRS complex tachycardia with negative precordial concordance was induced. A diagnosis of orthodromic atrioventricular re-entrant tachycardia involving a left lateral accessory pathway with left bundle branch aberration was made. This case represents a rare exception to the rule that negative precordial QRS concordance is diagnostic of ventricular tachycardia.

Excessive vagal response during left atrial ablation in a patient with paroxysmal atrial fibrillation.

Vagal reflexes can be induced by stimulation of select epicardial and endocardial areas of the left atrium. The present report describes the case of a 54-year-old woman with a history of recurrent symptomatic episodes of paroxysmal atrial fibrillation. During radiofrequency application around the left superior pulmonary vein, the patient exhibited an excessive vagal response with a sinus pause of 17 s.

Predictors of atrial fibrillation recurrence in patients with long-lasting atrial fibrillation.

BACKGROUND: Limited data are available on the predictors of atrial fibrillation (AF) recurrence in patients with chronic AF. OBJECTIVES: To evaluate potential clinical, echocardiographic and electrophysiological predictors of AF recurrence, after internal cardioversion for long-lasting AF. METHODS: A total of 99 consecutive patients (63 men and 36 women, mean age 63.33+/-9.27 years) with long-standing AF (52.42+/-72.02 months) underwent internal cardioversion with a catheter that consisted of two defibrillating coils. Shocks were delivered according to a step-up protocol. Clinical follow-up and electrocardiographic recordings were performed on a monthly basis for a 12-month period or whenever patients experienced symptoms suggestive of recurrent AF. RESULTS: Ninety-three patients (93.94%) underwent a successful uncomplicated cardioversion, with a mean atrial defibrillation threshold of 10.69+/-6.76 J. Immediate reinitiation of AF was observed in 15 patients (15.78%) of whom a repeated cardioversion restored sinus rhythm in 13 cases. Early recurrence of AF (within one week) was observed in 12 of 93 patients (12.90%). At the end of the 12-month follow-up period, during which seven patients were lost, 42 of the 86 remaining patients (48.84%) were still in sinus rhythm. Multivariate regression analysis showed that left atrial diameter (OR 1.126, 95% CI 1.015 to 1.249; P=0.025) and mitral A wave velocity (OR 0.972, 95% CI 0.945 to 0.999; P=0.044) were significant and independent predictors of AF recurrence, whereas age, left ventricular ejection fraction and AF cycle length were not predictive of arrhythmia recurrence. CONCLUSION: The present study showed that the left atrial diameter and mitral A wave velocity are the only variables associated with AF recurrence after successful cardioversion.

Determinants of plasma NT-pro-BNP levels in patients with atrial fibrillation and preserved left ventricular ejection fraction.

OBJECTIVES: The present study aimed to investigate the clinical and echocardiographic determinants of plasma NT-pro-BNP levels in patients with atrial fibrillation (AF) and preserved left ventricular ejection fraction (LVEF). METHODS: NT-pro-BNP levels were measured in 45 patients with paroxysmal AF, 41 patients with permanent AF and 48 controls. RESULTS: NT-pro-BNP levels were found significantly elevated in patients with paroxysmal (215+/-815 pg/ml) and permanent AF (1,086+/-835 pg/ml) in relation to control population (86.3+/-77.9 pg/ml) (P<0.001). According to the univariate linear regression analysis, age, hypertension, beta-blocker use, left atrial diameter (LAD), LVEF and AF status (paroxysmal or permanent or both) were significantly associated with NT-pro-BNP levels (P<0.05). In multiple linear regression analysis, LVEF (B coefficient: -53.030; CI: -95.738 to -10.322; P: 0.015) and LAD (B coefficient: 285.858; CI: 23.731-547.986; P: 0.033) were significant and independent determinants of NT-pro-BNP levels. CONCLUSIONS: Plasma NT-pro-BNP levels were significantly higher in patients with paroxysmal and permanent AF compared to those with sinus rhythm in the setting of preserved left ventricular systolic function. LVEF and LAD were independent predictors of NT-pro-BNP levels.

ECG findings of acute myocardial infarction and atrioventricular block during a transseptal procedure for left atrial ablation.

We report on a patient with transient atrioventricular block and ST-segment elevation mimicking the ECG of myocardial infarction during transseptal puncture for radiofrequency catheter ablation of atrial fibrillation. Symptoms and EGG findings resolved spontaneously. A neurally-mediated mechanism, activated by the mechanical effects of the transseptal puncture on the interatrial septum and leading to coronary artery spasm, may be considered as a possible explanation of this phenomenon. Coronary artery embolism following the transseptal procedure represents an alternative mechanism. The above mechanisms could also explain the atrioventricular block.

Neurally mediated susceptibility in individuals with Brugada-type ECG pattern.

BACKGROUND: Neurally mediated syncope and Brugada syndrome (BS) share common pathophysiologic mechanisms related to autonomic nervous system modulations, and particularly with increased vagal tone. This study aimed to investigate the incidence of neurally mediated susceptibility in individuals with Brugada-type electrocardiogram (ECG) pattern. METHODS AND RESULTS: Eight asymptomatic male individuals (mean age 41.6 +/- 10.6 years) with spontaneous or procainamide-induced type 1 ECG pattern of BS and structurally normal hearts underwent a drug-free head-up tilt test. Twenty-five healthy male subjects (mean age 37.4 +/- 14.1 years) with normal ECG and without structural heart disease were included in the study, and served as comparative controls. A positive tilt test response was observed in three out of eight subjects with the Brugada-type ECG pattern (37%) and in three out of 25 controls (12%) (P = 0.018). CONCLUSIONS: This study demonstrates a high incidence of neurally mediated susceptibility in asymptomatic individuals with Brugada-type ECG pattern. Severe diagnostic and therapeutic dilemmas may rise from this coexistence. A positive tilt test in subjects with Brugada-type ECG displaying a history of syncope may mislead the physician to a false sense of security. Further studies are required to validate our findings and possibly evaluate the role of tilt test in risk stratification of patients with BS.

Ablation of atrial fibrillation in patients with heart failure: reversal of atrial and ventricular remodelling.

INTRODUCTION: The management of patients with heart failure and atrial fibrillation (AF) is a medical challenge, especially in the case of patients in whom sinus rhythm or rate control cannot be achieved with optimal pharmaceutical treatment. METHODS: Thirteen consecutive patients (11 men and 2 women, 35-70 years old, median age 55 +/- 23 years) with heart failure (NYHA I-IV, median ejection fraction 35 +/- 5%, range 25-40%) and symptomatic persistent (10 patients, 76.9%) or permanent (3 patients, 23.1%) AF, underwent circumferential ablation using a system of electroanatomic mapping with contact. Circumferential ablation, encircling the pulmonary veins in pairs, and linear ablation between the left and right superior pulmonary vein and along the mitral isthmus were performed. Follow up included 24-hour Holter monitoring and transthoracic echocardiogram at 1, 3, 6, 9 and 12 months. RESULTS: Eight patients (62%) remained in sinus rhythm at the end of the follow up and had achieved a statistically significant improvement in ejection fraction (from 37.5 8.75% to 60.0 +/- 3.75%, p = 0.011), reduction of left ventricular end-diastolic diameter (from 63.0 +/- 3.25 mm to 56.5 +/- 1.75 mm, p = 0.011) and reduction of left atrial diameter (from 49.0 +/- 5.5 mm to 44.5 +/- 4.25 mm, p = 0.011). In contrast, patients with relapse of AF had none of the above changes (p > 0.05). Prognostic indexes of AF recurrence appeared to be the failure to improve ejection fraction (p = 0.003), non-reversal of left ventricular (p = 0.002) and left atrial (p = 0.006) remodelling, a shorter energy application time (p = 0.030) and the presence of coronary artery disease (p = 0.035). None of the patients suffered any complication from the procedure. CONCLUSION: AF ablation in selected patients with heart failure and low ejection fraction is a relatively effective method of maintaining sinus rhythm, improving left ventricular systolic function and reversing atrial and ventricular remodelling.

Reversal of premature ventricular complex-induced cardiomyopathy following successful radiofrequency catheter ablation.

Premature ventricular complex (PVC)-induced cardiomyopathy is an underappreciated cause of left-ventricular (LV) dysfunction. The present report describes the case of an elderly man with a very high burden of monomorphic PVCs and LV dysfunction. Elimination of the left ventricular focus following radiofrequency catheter ablation resulted in reversal of cardiomyopathy.

Prevalence of Brugada sign in a Greek tertiary hospital population.

AIMS: The purpose of the present study was to determine for the first time the prevalence of Brugada-type electrocardiographic (ECG) pattern (Brugada sign) in unselected individuals served by an urban Greek tertiary hospital during a 4-year time period. METHODS AND RESULTS: Among 11,488 individuals (6640 males, 4848 females), 25 (23 males, 2 females, aged 36.8 +/- 19.2 years) were found to display the Brugada sign (0.22%). Two cases exhibited the diagnostic type 1 ECG pattern (0.02%) and 23 subjects fulfilled the ECG criteria for type 2 or 3 patterns (0.2%). The incidence of Brugada sign was higher among men (0.34%) than in women (0.04%). Structural heart disease was established in four cases (one of them exhibiting a type 1 ECG pattern). Twenty-one individuals (19 males, 2 females, aged 29.7 +/- 10.7 years) without structural heart disease displaying Brugada-type ECG features (4 cases with spontaneous or procainamide-induced type 1 ECG pattern) were subsequently selected and closely followed up for 24 +/- 12 months. No mortality or life-threatening ventricular arrhythmias were recorded during this period. CONCLUSION: The Brugada-type ECG pattern is infrequently seen in a Greek hospital-based population. All subjects with Brugada sign and structurally normal hearts displayed a benign clinical course without arrhythmic events during a relatively long follow-up period.

Enterovirus-induced fulminant myocarditis and hemophagocytic syndrome.

We report the case of a 17-year-old male who was admitted to the emergency department in cardiogenic shock and multiorgan failure due to fulminant myocarditis. The following days the patient developed anemia, thrombocytopenia, and hepatosplenomegaly. Bone marrow examination showed many mature histiocytes with active hemophagocytosis. Nested reverse transcriptase-PCR molecular analysis of blood samples and sequencing of the amplified alleles confirmed enteroviral infection. Our patient was treated with inotropic agents and immunoglobulin, and recovered completely. This is the first report that documents concomitant presentation of fulminant myocarditis and hemophagocytic syndrome due to enteroviral infection.

ST-segment elevation induced during the transseptal procedure for radiofrequency catheter ablation of atrial fibrillation.

We report two cases of transient coronary artery ischemia manifested as chest discomfort with ST-segment elevation in inferior leads during the transseptal procedure for radiofrequency catheter ablation of atrial fibrillation. This unexpected complication was resolved by intravenous administration of nitrates. All patients exhibited normal coronary arteries in angiography. A neurally mediated pathway activated by the mechanical effects of the transseptal puncture on the interatrial vagal network leading to coronary artery spasm may be considered as a possible explanation of this phenomenon. Coronary artery embolism following the transseptal procedure represents a different underlying mechanism.

Secondary prevention of sudden cardiac death in coronary artery spasm: is implantable cardioverter defibrillator always efficient?

Syncope and/or cardiac arrest in the setting of coronary artery spasm have been associated with atrioventricular block and asystole or ventricular tachyarrhythmias. Ventricular arrhythmias have been predominantly reported in cases of multivessel coronary artery spasm. The present report highlights the case of a young woman who suffered repeated episodes of multivessel coronary artery spasm in association with polymorphic ventricular tachycardia and cardiac arrest. The efficacy of implantable cardioverter defibrillator in secondary prevention of sudden cardiac death due to coronary artery spasm is discussed.

Swimming-triggered aborted sudden cardiac death in a patient with Andersen-Tawil syndrome.

In this report we describe the case of a 42-year-old woman who experienced an episode of near drowning during recreational swimming. A diagnosis of Andersen-Tawil syndrome was made based on the patient's dysmorphic features, characteristic T-U-wave patterns and ventricular arrhythmias. To our knowledge, this is the first report of a swimming-triggered cardiac event in a patient with Andersen-Tawil syndrome.

Open ended circulation pattern: a rare case of a protective coronary artery variation and review of the literature.

Persistent intercoronary communications, forming the so-called open ended coronary circulation pattern, are rare findings of coronary angiography. A case of intercoronary connection between the left anterior descending artery (LAD) and the right coronary artery (RCA), with an obstructive lesion, and no evidence of myocardial infarction is presented. This is an exceptional variant, only 20 cases of which were found in the literature. The potential protective role of this anomaly against occlusive coronary artery disease is discussed and similar reports are reviewed.

Drug-induced QT interval prolongation after ciprofloxacin administration in a patient receiving olanzapine.

Several non-antiarrhythmic drugs including antibiotic and antipsychotic agents have been shown to prolong cardiac repolarization predisposing to torsade de pointes ventricular tachycardia. Blockade of the delayed rectifier (repolarising) potassium current and drug interactions with inhibitors of the CYP-mediated metabolism are the most common underlying mechanisms. In the present case report, an elderly woman receiving a long-term medication with azathioprine, olanzapine and valsartan developed a marked QT interval prolongation after intravenous administration of ciprofloxacin.