Atrioventricular Nodal Reentrant Tachycardia with Paroxysmal Atrial Fibrillation: Clinical and Electrophysiological Features and Predictors of Atrial Fibrillation Recurrence Following Elimination of Atrioventricular Nodal Reentrant Tachycardia

Introduction: Clinical and electrophysiological characteristics of patients with atrioventricular nodal reentrant tachycardia (AVNRT) and paroxysmal atrial fibrillation (AF) have not been studied in a large patient cohort. We aimed to define the clinical features and cardiac electrophysiological characteristics of these patients, and to examine the incidence and identify predictors of AF recurrences after elimination of AVNRT. Methods and Results: Thirty-six patients with AVNRT and documented paroxysmal AF (Group 1) and 497 patients with AVNRT alone undergoing ablation in the same period (Group 2) were studied. There were no significant differences between groups regarding clinical features, except age, which was higher in Group 1 (p < 0.001). Presence of atrial vulnerability (induction of AF lasting > 30 seconds) and multiple AH jumps (≥50 ms) before ablation were significantly more prevalent in Group 1 (p < 0.001, p = 0.010 respectively). During follow-up of 34 ± 11 months, AF recurred in 10 patients (28%) in Group 1, while 2 patients in Group 2 (0.4%) developed paroxysmal AF (p < 0.001). Univariate predictors of AF were: left atrial diameter > 40 mm (p = 0.001), presence of mitral or aortic calcification (p = 0.003), atrial vulnerability after ablation (p = 0.015) and valvular disease (p = 0.042). However, independent predictors of AF recurrences were left atrial diameter > 40 mm (p = 0.002) and the presence of atrial vulnerability after ablation (p = 0.034). Conclusion: In patients with both AVNRT and paroxysmal AF, the recurrence rate of AF after elimination of AVNRT is 28%. Left atrial diameter greater than 40 mm and atrial vulnerability after elimination of AVNRT are independent predictors of AF recurrences in the long term.     

Does Coronary Artery Size Really Matter?

OBJECTIVE: To evaluate ischemia in right ventricle (RV) in patients with small caliber of right coronary artery (RCA). PATIENTS AND METHODS: The study population consisted of 60 consecutive patients undergoing coronary angiography within 3 months. The patients were divided into three different groups according to lumen diameter of RCA and coronary dominance. Group 1, 2, and 3 consisted of patients with small diameter of RCA, dominant RCA, and dominant circumflex artery, respectively. RV ischemia was assessed by using pulse-wave tissue Doppler sampling obtained from RV free wall close to the lateral tricuspid annulus at the apical four-chamber view during dobutamine stress echocardiography (DSE). RESULTS: When the mean systolic velocity percentages of increase from low to peak dose dobutamine in patients with small RCA were compared to those of other groups, statistically significant difference was found between group 1 and the other groups (P = 0.007 for group 1 vs group 2; P = 0.01 for group 1 vs group 3). The mean systolic velocity at peak dobutamine dose of patients with small caliber of right coronary artery was statistically lower than the other groups (P = 0.001 for group 1 vs group 2, P < 0.001 group 1 vs group 3). CONCLUSIONS: There are a group of patients with small diameter of RCA causing probable ischemia in RV and small caliber of RCA can really matter in these patients.     

Electrical injury as a possible cause of sick sinus syndrome

Electrical injury is a serious public health problem. Heart is one of the most frequently affected organs. Electrical injury can cause life-threatening cardiac complications such as asystole, ventricular fibrillation, and myocardial rupture. In this case report, we present a 20-yr-old male patient with sick sinus syndrome that developed years after electrical injury.     

Single coronary artery with anomalous origin of the right coronary artery from the left anterior descending artery with a unique proximal course

A 62-year-old man with hypertension and hypercholesterolemia was referred to our unit for evaluation of chest pain. A very rare variant of single coronary artery, in which the anomalous right coronary artery originated as a separate branch from the left anterior descending artery, was incidentally found on his coronary angiography. The anomalous right coronary artery in our case appears to be unique in that it courses intraseptally rather than rightwards proximally and has obstructive atherosclerotic lesions resulting in inferior ischemia. Moreover, the acute angle made by the anomalous right coronary artery to turn toward the atrioventricular groove may have reduced the flow velocity and contributed to the development of inferior ischemia.     

Angiographic restenosis after myocardial bridge stenting

Data on restenosis after stent implantation in myocardial bridges (MB) are very limited. Six-month angiographic results for 12 symptomatic patients who underwent stent implantation for myocardial bridges were compared retrospectively with those of 39 patients who underwent direct stent implantation for de novo atherosclerotic lesions in the left anterior descending artery. Diameter stenosis decreased from 69 +/- 8% to 4 +/- 5% in the MB group and from 79 +/- 8% to 7 +/- 6% in the control group after stent deployment. Systolic narrowing was abolished in all patients with MB. In follow-up, quantitative angiography revealed late loss of 1.8 +/- 1.3 mm in the MB group and 0.9 +/- 0.9 mm in the control group (P = 0.025). The in-stent restenosis rate was also higher in the MB group compared to the control group (67% versus 28%; P = 0.037). Despite favorable immediate results, stent implantation in MBs may not be promising because of the higher in-stent restenosis rate compared to stenting in de novo atherosclerotic lesions.     

Increased P Wave Dispersion and Maximum P Wave Duration after Hemodialysis

Background: Atrial fibrillation is a frequent arrhythmia in patients undergoing hemodialysis. The consequences of hemodialysis on P wave durations and P wave dispersion have not been fully understood. The objective of this study was to study the effect of dialysis on P wave maximum (P_max), P wave minimum (P_min), and P wave dispersion (P_d). Methods: We studied P_max, P_min, and P_d in 32 patients (17 men and 15 women, mean age 54 ± 18 years) with chronic renal failure undergoing hemodialysis. The difference between maximum and minimum P wave duration was calculated and defined as P wave dispersion (P_d= P_max? P_min). Results: There was a significant increase in P_max at the end of dialysis compared to the beginning (98 ± 13 ms vs. 125 ± 12 ms, P < 0.001). P_min did not show any significant change (71 ± 11 ms vs. 73 ± 10 ms, P = 0.42). P_d was significantly increased at the end of dialysis (27 ± 9 ms vs. 52 ± 11 ms, P < 0.001). There was a negative correlation between serum potassium, magnesium, phosphate, blood urea nitrogen, and creatinin at the end of dialysis and P_max and P_d, respectively (P < 0.05). A weak positive correlation was found between serum calcium, bicarbonate at the end of dialysis and P_max and P_d (P < 0.05). Conclusion: Hemodialysis ends with significant increase in P wave maximum duration and P wave dispersion, which might be responsible for the increased occurrence of atrial fibrillation in these groups of patients.     

Frequency of chromosome 17 aneuploidy in primary and recurrent pterygium by interphase-fluorescence in situ hybridization

AIM: To investigate chromosome 17 numerical aberrations by using fluorescence in situ hybridization (FISH) in pterygia and to find out whether there is any association between chromosome 17 aneuploidy and recurrent pterygia. METHODS: Pterygium tissue samples were taken from 21 patients by surgical excision. Eighteen of them had primary and 3 had recurrent pterygium. Peripheral whole blood interphase cells obtained from 11 healthy subjects were assigned as control group. The cells from pterygium tissue and peripheral blood were incubated with a hypotonic solution and fixed in order to obtain interphase nuclei. FISH analysis with chromosome-17-specific alpha-satellite DNA probe was performed on both the interphase nuclei of pterygium tissue (of patients) and peripheral whole blood cells of controls. RESULTS: The mean percentage of chromosome 17 aneuploidy was 4.71% for the pterygia group and 4.41% for the controls. No significant difference of chromosome 17 aneuploidy was observed between the patients and the controls. When the group of patients with recurrences was compared with the group without recurrences, there was a significant difference in the frequency of chromosome 17 aneuploidy (U = 17, p = 0.029). CONCLUSIONs: Chromosome 17 aneuploidy is probably not an important factor in the formation of pterygium, but it may be related to recurrence.