Persistent isolated right atrial standstill associated with left atrial tachycardia

Introduction:

Atrial standstill is a rare condition, characterized by absence of atrial electrical and mechanical activity evident in surface electrocardiography echocardiography, or fluoroscopy, which is associated with unresponsiveness of atria to maximal output electrical stimulation. This condition can be present with thromboembolic complication, low cardiac output, and sometimes palpitation.

Case Presentation:

Here we presented a woman with right atrial stand still and left atrial tachycardia. It was confirmed by electrocardiogram, echocardiography, and intracardiac electrogram in basal state and during maximal output electrical stimulation. We treated her by implanting pacemaker to control bradycardia, oral calcium channel blocker to control palpitation episodes, and anticoagulation.

Conclusions:

Atrial standstill can be present partially that can be localized in one atrium and is associated with tachycardia in the other atrium.

Randomized Prospective Comparison of Two Protocols for Head-up Tilt Testing in Patients with Normal Heart and Recurrent Unexplained Syncope

BACKGROUND

This randomized study was aimed to compare the diagnostic value of two head-up tilt testing protocols using sublingual nitroglycerin for provocation in patients with recurrent unexplained syncope and normal heart.

METHODS

The patients with normal findings in physical examination, electrocardiography and echocardiography were randomly submitted to one of upright tilt test protocols. The only difference between two protocols was that nitroglycerin was administered after a five minute resting phase in supine position during protocol B. We also considered eighty normal persons as the control group.

RESULTS

Out of 290 patients that underwent tilt testing, 132 patients were in group A versus 158 patients in group B. Both groups had an identical distribution of clinical characteristics. Tilt test was positive in 79 patients in group A (25 in passive phase, 54 in active phase) versus 96 patients in group B (43 in passive phase, 53 in active phase). There was no significant difference between results in two groups (P value= 0.127). Forty cases were tested with protocol A and forty underwent tilt testing with protocol B. Tilt test was positive in 4 cases with protocol A versus 3 cases in protocol B. The positive rates of tilt testing with protocol A was 60% while it was 61% in protocol B. The specificity of testing with protocol A was 90% and it was 92.5% in protocol B.

CONCLUSIONS

According to our data, adding a period of rest and returning to supine position before nitroglycerin administration had no additional diagnostic yield.

Effects of right ventricular septal versus apical pacing on plasma natriuretic peptide levels

Background:

To investigate the contribution of right ventricular (RV) pacing sites to the cardiac function, this study compares plasma B-type natriuretic peptide (BNP) levels during RV septal and apical pacing in patients implanted with a pacemaker.

Materials and Methods and Results:

Seventy-four consecutive patients with indication for permanent pacing were included. To provide for the possibility of appropriate subgroup analyses, patients were stratified according to their pacing mode into two groups: Those with dual chamber DDD(R)/VDD pacemakers (41 patients, mean age 54.1±18.4 years), and those with single chamber VVI pacemakers (33 patients, mean age 60.6±18.4 years). A prospective single-blinded randomized design was used. Randomization (1:1 way) was between lead placement on the RV septum or RV apex and occurred during the implant in both groups. Compared to baseline, a significant decrease in BNP (429.8±103 pg/ml and 291.7±138 pg/ml, respectively) levels was observed during DDD(R) /VDD pacing after two months. In contrast, during VVI (R) pacing, a significant increase in BNP levels was observed (657.5±104 pg/ml and 889.5±139 pg/ml, respectively). To determine the impact of pacing sites on cardiac function, we assessed the changes in BNP levels in each group separately. Despite the significant difference in the pattern of changes between the two groups (P < 0.02), no significant changes were observed within groups regarding the acute effect of the pacing site (RV apex vs. RV septal) on BNP levels (P=NS).

Conclusions:

Our main result showed no significant differences between pacing sites and concluded that hemodynamic improvement could be substantially influenced by pacing mode, more than by pacing site.

Spontaneous alternans in Brugada ECG morphology

A 23-year-old man presented with sick sinus syndrome and Brugada-like ECG pattern. Coved type ECG (type 1) converted to saddleback configuration (type 2) when R-R interval decreased and it changed to coved type pattern with increasing R-R cycle length. During stable heart rate, there was no change in Brugada ECG pattern. The R-R interval effect on these patterns can be explained by intensity or kinetics of ion currents and autonomic tone.

Mid-term follow-up of patients with Brugada syndrome following a cardioverter defibrillator implantation: a single center experience

BACKGROUND

Brugada syndrome is an arrhythmogenic disease characterized by an ECG pattern of ST-segment elevation in the right precordial leads and an increase risk of sudden cardiac death. Risk stratification for the life-threatening arrhythmic events in Brugada syndrome is not yet established. In the present study, we report our experience in patients with Brugada syndrome, following an ICD implantation.

METHODS AND RESULTS

A total of 12 patients (11 men, 1 woman) with a mean age of 46.5+/-11.8 were studied. At diagnosis, 7 patients had syncope of unknown origin, 2 patients were asymptomatic, 2 patients were survivors of cardiac arrest, and 1 had documented clinical VT requiring direct cardioversion for termination. Age was similar between the symptomatic and asymptomatic patients (46.6+/-13 vs. 46+/-2.8, respectively). Two patients reported a family history of sudden cardiac death. In 3 patients, spontaneous coved-type ECG was found at baseline. In 9 patients, a class I antiarrhythmic drug administration unmasked the characteristic type I ECG. In 4 patients (2 symptomatic with syncope at presentation and 2 asymptomatic), who underwent PES, sustained polymorphic VT or VF was induced. VF was induced by single extrastimuli in 2 symptomatic patients (1 from RV apex and 1 from RVOT). In 2 asymptomatic patients, VF was induced by two and triple ventricular extrastimli (1 from RV apex and 1 from RVOT). None of them experienced an event during follow-up. No significant difference was found between symptomatic and asymptomatic patients (p=NS). The mean follow-up period for the entire study population was 27.83+/-11.25 months. During follow-up, 2 patients (one with prior cardiac arrest and another with syncope) had VF. Both of them had a type I ECG after provocation with a class I antiarrhythmic drug. None of them had undergone programmed ventricular stimulation. Five patients (41.7 %) had inappropriate ICD interventions during follow-up. The cause of inappropriate therapy was sinus tachycardia in 2 patients, AF in 2 patients and T wave oversensing in 1 patient.

CONCLUSION

Knowledge about Brugada syndrome is steadily progressing but there are still unanswered issues dealing with the risk stratification and the management of patients.

A patient with sick sinus syndrome, atrial flutter and bidirectional ventricular tachycardia: Coincident or concomitant presentations?

Channelopathies are among the major causes of syncope or sudden cardiac death in patients with structurally normal hearts. In these patients, the atrium, ventricle or both could be affected and reveal different presentations. In this case, we present a patient with an apparently structurally normal heart and recurrent syncope, presented as sick sinus syndrome with atrial flutter and bidirectional ventricular tachycardia. (Cardiol J 2007; 14: 585-588).

Effect of first ventricular tachycardia cycle length on rate of ventricular arrhythmia recurrence in patients with implantable cardioverter-defibrillator

BACKGROUND

Some controversies exist regarding the proper treatment of hemodynamically tolerated and slow ventricular tachycardia (VT). We intended to assess the effect of cycle length of first VT episode on total ventricular arrhythmia burden in a cohort of patients with implantable cardioverter-defibrillator (ICD).

METHOD

Between March 2000 and March 2005, 195 patients underwent ICD implantation at our center. We included 158 patients (mean age, 58.3 +/- 12.9 years) with follow-up of 3 months or more in this study. Clinical, electrocardiographic, and ICD-stored data and electrograms were collected and analyzed.

RESULTS

During the follow-up of 16.7 +/- 10.6 months, 45 (28.5%) and 20 (12.6%) patients received first appropriate ICD therapy for VT and ventricular fibrillation, respectively. We divided the 45 patients with VT (based on the median value of VT cycle length) into 2 groups. Although patients with VT cycle length of less than 350 had higher total mean number of appropriate ICD therapy (25 vs 6.3, P = .023), during multivariate regression analysis, only left ventricular ejection fraction (EF) of less than 25% (P = .020) was correlated with total number of appropriate ICD therapy. First VT cycle length (P = .341), QRS duration (P = .126), age (P = .405), underlying heart disease (P = .310), indication of ICD implantation (P = .113), and sex (P = .886) have failed to predict the total burden of ventricular arrhythmia during the follow-up period.

CONCLUSION

After adjustment for left ventricular EF, initial VT cycle length per se did not confer a lower risk for subsequent ventricular arrhythmia recurrence compared with those with faster VT. Left ventricular EF of less than 25% was correlated with higher ventricular arrhythmia burden in patients with ICD.

Predictors of appropriate ICD therapy in patients with implantable cardioverter-defibrillator

BACKGROUND

Understanding the predictors of appropriate implantable cardioverter defibrillator (ICD) therapy could help to better identify candidates for ICD implantation.

METHODS

One hundred and sixty two patients with ICD (111 with coronary artery disease [CAD] and 51 with dilated cardiomyopathy [DCM]) were included in the study. Clinical, electrocardiographic, and ICD stored data and electrograms were collected.

RESULTS

During mean follow up of 15+/-11 months 54 patients (33%) received > or = 1 appropriate ICD therapy (AICDT). We used binary logistic regression analysis with forward selection method to find the potential predictors of appropriate ICD therapy after device implantation. Male gender (odds ratio [OR] = 2.76, 95% confidence interval [CI] = 1.1-7.1, P=0.021), DCM as underlying heart disease (OR = 4.2, 95% CI = 1.9-9.5, P=0.001), and QRS width > 100 ms (OR = 2.58, 95% CI = 1.2-5.4, P=0.010) were correlated with increased likelihood of AICDT during the follow up period. In subgroup analysis of the patients with CAD and DCM, QRS duration > 100 ms was correlated with the probability of > or = 1 AICDT. In our patients indication of ICD implantation (primary versus secondary prevention) did not influence probability of > or = 1 AICDT (adjusted OR = 1.66, 95% CI = 0.7-4.0, Mantel-Haenszel P value P=0.355).

CONCLUSION

QRS width could be used as an additional simple risk stratifier beyond EF to identify potential candidates who would benefit more from ICD implantation. This may have practical implications for patient selection especially in developing countries. Indication of ICD implantation (primary versus secondary prevention) did not affect the probability of > or = 1 AICDT during the follow up period.