Gamma-glutamyl transferase predicts recurrences of atrial fibrillation after catheter ablation.

BACKGROUND: Catheter ablation is a popular therapy of atrial fibrillation (AF). Gamma-glutamyl transferase (GGT) is known as a marker of oxidative stress. The objective of this study was to ascertain the relationship between levels of GGT and recurrence of AF after catheter ablation. METHODS: A total of 102 paroxysmal AF patients who underwent cryoballoon catheter ablation were enrolled. Serum samples were obtained to evaluate GGT levels before catheter ablation. Cox regression analysis was used to estimate the predictors of AF recurrence. RESULTS: Mean age of the cohort was 49.9 ± 11.7 and 63% of the patients were male. After a mean follow-up of 20 months, 19 (23%) patients had AF recurrences. The baseline GGT levels were significantly higher in patients who had AF recurrence [27 U/L (17-36) vs 18 U/L (13-22), P = 0.002]. The optimal cut-off value of GGT to predict AF recurrence was 23.5 U/L according to receiver operating characteristic curve analysis (area under the curve 0.72, P = 0.002). In the multivariable Cox regression analysis, baseline GGT > 23.5 was the only independent predictor of AF recurrence (hazard ratio (HR) 4.47, 95% confidence interval [1.66-12.09], P = 0.003). CONCLUSIONS: Our results indicate that elevated GGT is associated with AF recurrence. A simple measurement of GGT may help us to identify high-risk patients undergoing catheter ablation for AF.

N-terminal pro-brain natriuretic peptide and electrocardiographic variables associated with increased risk of complete atrioventricular block and mortality in patients with acute inferior myocardial infarction.

BACKGROUND: Although brain natriuretic peptide (BNP) levels are shown to be an important prognostic factor in patients with acute myocardial infarction (MI), the relationship between arrhythmias and BNP levels is not known. This study assessed whether baseline clinical factors, N-terminal-proBNP (NT-proBNP) levels and electrocardiographic patterns of acute inferior MI are associated with greater risk of developing complete atrioventricular block (CAVB) and mortality. METHODS AND RESULTS: Seventy-nine consecutive patients (52 male, 27 female with an avarage age of 64.2 ± 10.9 years) with CAVB and 119 control patients (93 male, 16 female with an average age of 57.7 ± 11.4 years) without CAVB were enrolled. Regression analysis revealed that NT-proBNP levels 〉 104 pg/mL increased the development of CAVB by 16.7 folds, 〉 1 mm ST elevation in RV4 by 2.7 folds, ratio of elevation in lead III:II 〉 1.5 by 10.1 folds but the thrombolytic therapy decreased the development of CAVB by 2.8 folds. NT-proBNP 〉 92 pg/mL increased the mortality by 8.9 folds, a ratio of ST-segment elevation in lead III:II 〉 1 by 3.1 folds, ST segment elevation 〉 1 mm in RV4 by 3.5 folds, ejection fraction 〈 35% by 24.2 folds, age 〉 65 years by 8.3 folds and CAVB by 6.8 folds, on contrary thrombolytic treatment decreased the mortality by 3.3 folds. CONCLUSIONS: Simple electrocardiographic measurements and NT-proBNP levels at admission can be used as a screening test for development of complications such as CAVB, right ventricular involvement and mortality during acute inferior wall MI.

Relationship between endothelial functions and acetylsalicylic acid resistance in newly diagnosed hypertensive patients.

BACKGROUND: We aimed to investigate the effects and dose dependency of aspirin on endothelial functions and prevalence of aspirin resistance in newly diagnosed hypertensive patients without previous drug therapy and development of cardiac complications. HYPOTHESIS: Acetylsalicyclic acid improves endothelial function. METHODS: Fifty-eight hypertensive patients and 61 healthy subjects in the control group were included in the study. Endothelial functions of the patient and control groups were evaluated with brachial artery examination. Patient and control groups were divided into 2 groups. A total of 100 mg and 300 mg of aspirin were given to the separate groups for 1 week. After 1 week, endothelial functions were reevaluated and aspirin resistance examined with a platelet function analyzer (PFA-100; Dade Behring, Marbourg, Germany). RESULTS: Baseline flow-mediated dilatation (FMD) change percent in hypertensive patients was 9.8%, and it was significantly lower than in the control group (12%) (P < 0.001). Frequency of acetylsalicylic acid (ASA) resistance was 20% and 26% in control and hypertensive patient groups, respectively (P = not significant). ASA resistance was 28% and 24% in 100 mg and 300 mg in hypertensive patients, respectively (P = not significant). FMD change percent increased both in the control and hypertensive groups after ASA treatment from 12.4% to 13.3% and 9.8 % to 11.9 %, respectively. FMD percentage change was significantly increased in hypertensive patients irrespective of ASA resistance (P = 0.02, for ASA resistance [+]; P < 0.012, for ASA resistance [-]). CONCLUSIONS: Endothelial functions were impaired more in hypertensive patients compared to the control group. Endothelial functions were improved with all ASA doses in hypertensive patients irrespective of ASA resistance.

Effect of cardiac resynchronization therapy on thyroid function.

BACKGROUND: Heart failure patients frequently have thyroid function abnormalities. Cardiac resynchronization therapy (CRT) is a major treatment for patients with advanced chronic heart failure. We aimed to investigate the effects of CRT on thyroid functions. HYPOTHESIS: CRT improves thyroid functions. METHODS: Fifty-seven patients (42 male, 15 female; mean age 58 ± 13 y) undergoing CRT were included in the study. Serum levels of thyroid hormones and echocardiographic parameters were measured before and 6 months after CRT. A response to CRT was defined as a reverse remodeling detected by a relative increase of ≥15% in left ventricular ejection fraction. RESULTS: The clinical status and functional capacity of the patients in the remodeling group were improved significantly. The mean New York Heart Association class was reduced from 3.2 ± 0.4 to 2.2 ± 0.4 (P<0.001). The free triiodothyronine (fT3) level increased from 2.67 pg/mL to 2.97 pg/mL in the reverse remodeling group (P = 0.005). The fT3/fT4 ratio increased from 1.81 to 2.34 (P = 0.006). CONCLUSIONS: CRT improves fT3 levels and fT3/fT4 ratio, which may play an important role in reverse remodeling.

Plasma levels of tumor necrosis factor-alpha and its receptors in patients with mitral stenosis and sinus rhythm undergoing percutaneous balloon valvuloplasty.

This study aimed to determine whether plasma levels of tumor necrosis factor-alpha (TNF-alpha) and soluble TNF receptor (sTNF-R) increases in rheumatic mitral stenosis (MS) patients with sinus rhythm and to examine the effect of percutaneous mitral balloon valvuloplasty (PMBV) on these parameters. Twenty-six patients with MS and sinus rhythm (study group, 20 female, mean age 33 +/- 8 years), who were scheduled for PMBV, and a well-matched control group consisting of 21 healthy volunteers (15 female, mean age 35 +/- 6 years) were enrolled in the study. Tumor necrosis factor-alpha and sTNF-R levels were compared between study patients and controls, and between peripheral and left atrium (LA) blood. Changes in TNF alpha and sTNF-R levels 24 h and 4 weeks after PMBV were analyzed. Significantly higher baseline TNF-alpha and sTNF-R levels were noted in the study group. In the study group, TNF-alpha and its receptors were also found to be higher in LA blood than in baseline peripheral blood. After PMBV, mitral valve area (MVA) increased and transmitral pressure gradient decreased significantly. At the 24th hour after PMBV, the TNF-alpha level decreased from 29.61 +/- 12.22 pg/ml to 22.42 +/- 8.81 pg/ml (P < 0.0001) and at the 4th week, from 22.42 +/- 8.81 pg/ml to 18.92 +/- 7.37 pg/ml (P < 0.0001). Similar reductions were observed in the sTNF-R level. Regression analysis between the difference in sTNF-R level measured 24 h after and before PMBV and the difference in MVA measured 24 h after and before PMBV showed a significant direct relationship between these variables. This study suggests that isolated rheumatic MS without atrial fibrillation is accompanied by increased TNF-alpha and sTNF-R level. The successful PMBV establishes a significant reduction in TNF-alpha and its receptors, probably due to improved postprocedural hemodynamic parameters.

Documentation of impaired coronary blood flow in chronic obstructive pulmonary disease patients.

BACKGROUND: In the current study, the effects of moderate to severe chronic obstructive pulmonary disease (COPD) on coronary blood flow in patients with angiographically proven normal coronary arteries was evaluated. METHODS AND RESULTS: A total of 85 patients with moderate to severe COPD and 39 age- and sex-matched control partcipants, who underwent diagnostic coronary angiography and found to have normal epicardial coronary angiogram constituted the COPD and control groups, respectively. The 2 groups were compared for Thrombolysis In Myocardial Infarction (TIMI) frame counts in each major coronary artery. The TIMI frame count of the COPD group was significantly higher than that of control group for all 3 major individual coronary arteries: left anterior descending (corrected), 37+/-13 vs 20+/-4; right coronary artery, 32+/-14 vs 21+/-4; and left circumflex artery, 34+/-12 vs 20+/-5, (P<0.001 for all). In addition, TIMI frame counts in individual coronary arteries were found to be positively correlated with forced expiratory volume 1 s percent, serum high sensitive C-reactive protein and fibrinogen concentrations, in the COPD group. CONCLUSIONS: Our findings suggest that an increased slow coronary flow might be a manifestation of harmful effects of COPD on the coronary circulation, regardless of the underlying mechanism.

The prevalence of aspirin resistance in patients with metabolic syndrome.

OBJECTIVES: Aspirin is recommended for primary prevention in patients with metabolic syndrome (MetS). In this study, we evaluated aspirin resistance in MetS patients. STUDY DESIGN: The study included 32 patients (23 males, 9 females; mean age 60.7+/-11.4 years) with the diagnosis of MetS, according to the criteria of the International Diabetes Federation. Aspirin resistance was determined by the PFA-100 analysis (Platelet Function Analyzer). The results were compared with a control group of 30 patients (16 males, 14 females; mean age 61.6+/-7.3 years) without MetS. All the patients were taking aspirin at the time of the PFA-100 analysis. RESULTS: Overall, 21 patients (33.9%) were aspirin nonresponders. The prevalence of aspirin resistance was 46.9% in the MetS group, and 20% in the control group. The difference between the two groups was statistically significant (p=0.033). Compared to aspirin responders, fasting blood glucose level was higher (102.0+/-14.6 mg/dl vs. 95.3+/-9.9 mg/dl; p=0.036) and waist circumference tended to be greater in nonresponders (97.4+/-14.1 cm vs. 89.7+/-15.0 cm; p=0.053). Multivariate logistic regression analysis showed that MetS (OR 0.28, 95% CI 0.09-0.88; p=0.029), fasting blood glucose (OR 0.95, 95% CI 0.91-0.99; p=0.045), uric acid (OR 0.46, 95% CI 0.28-0.76; p=0.002), gamma-glutamyl transferase (OR 1.04, 95% CI 1.00-1.08; p=0.043), high-sensitivity C-reactive protein (OR 1.07, 95% CI 1.01-1.12; p=0.015) levels and platelet count (OR 0.99, 95% CI 0.98-0.99; p=0.034) significantly affected aspirin resistance. CONCLUSION: Our results show that a significant proportion of MetS patients will not benefit from aspirin use due to high aspirin resistance.

P-wave durations in patients experiencing atrial fibrillation during exercise testing.

Augmented sympathoadrenal activity during exercise may contribute to occurrence of various arrhythmias including atrial fibrillation (AF). The prolongation of intraatrial and interatrial conduction times and inhomogeneous propagation of sinus impulses are well-known characteristics of the atrium prone to fibrillate and are evaluated by maximum P-wave duration (P max), P-wave dispersion (PWD). To show the increased P max and PWD values in patients experiencing AF during exercise testing and the role of beta blockade on treatment of exercise-induced AF, 22 of these patients were compared with a control group consisting of 41 patients without AF attacks. P max (p = 0.001) and PWD (p = 0.001) values were significantly higher in patients with AF compared to those without AF. The development of AF during exercise testing was found to be positively correlated with P max (r = 0.87, p < 0.001), PWD (r = 0.83, p = 0.001), and work load (r = 0.34, p = 0.002) and negatively correlated with ejection fraction (r = -0.26, p=0.02). After the treatment with beta-blocking agents for 2 weeks, the decrease in P max and PWD values was accompanied by a much lower prevalence of exercise-induced AF. Consequently, the patients with AF had greater P max and PWD values compared to control subjects, and these simple parameters were well correlated with the occurrence of AF during exercise testing. Furthermore, treatment of these patients with beta blockers would appear to decrease the recurrence of exercise-induced AF and to be associated with a decrease in P-wave durations.

Evaluation of effects of intra aortic balloon counterpulsation on autonomic nervous system functions by heart rate variability analysis.

BACKGROUND: In patients with acute myocardial infarction (AMI), intraaortic balloon counterpulsation (IABC) may improve cardiac performance, decrease the incidence of recurrent ischemia, and improve survival. Although there have been several reports concerning circulatory maintenance with the IABC, response of the autonomic nervous system to these hemodynamic changes is not clear. Heart rate variability (HRV) analysis has been extensively used to evaluate autonomic modulation of sinus node and to identify patients at risk for an increased cardiac mortality. In this study, we evaluated effects of the IABC on autonomic nervous system functions by HRV analysis. METHODS: The study group was composed of 32 consecutive patients (13 female, 19 male aged 61.8 +/- 8.8 years) undergoing IABC. Transthoracic echocardiography and 1-hour Holter recordings for HRV analysis in each IAB pumping mode were obtained. RESULTS: The IABC improved left ventricular diastolic and systolic functions as well as caused an increase in SDNN1, PNN50(1), RMSSD1, and HF1 and a decrease in LF1, LF/HF1, mean heart rate, and the number of ventricular extrasystoles. The improvements in HRV parameters were correlated with some hemodynamic changes such as the increase in MAP and CO during counterpulsation. The only independent factors affecting in-hospital mortality were the change in LF/HF1 ratio (DeltaLF/HF1) and the change in the number of ventricular extrasystole (DeltaVES). The decrease in LF/HF1 > or = 4.9 decreased the mortality by 1.7-folds (RR = 0.6, P = 0.04, 95% CI: 0.1-2.3). The decrease in VES > or = 27/15 minutes resulted in mortality reduction by 16-folds (RR = 0.06, P = 0.02, 95% CI: 0.01-0.4). CONCLUSIONS: As a result, the IABC, especially in 1:1 support, causes an increase in HRV, decrease in sympathetic overactivity, and improvement in sympathovagal balance besides the favorable hemodynamic changes, and these electrophysiologic changes may explain the role of the IABC in the treatment of ventricular arrhythmias.

Plasma level of soluble P-selectin in patients with rheumatic mitral stenosis and sinus rhythm undergoing percutaneous mitral balloon valvuloplasty.

OBJECTIVE: To determine whether plasma level of soluble P-selectin (sP-selectin) increases in rheumatic mitral stenosis (MS) patients with sinus rhythm, who have scheduled for percutaneous mitral balloon valvuloplasty (PMBV), and to examine the effect of PMBV on sP-selectin level. METHODS: Twenty-six patients with MS and sinus rhythm (study group, 20 female, mean age 33 +/- 8 years) and a well-matched control group composed of 21 healthy volunteers (15 female, mean age 35 +/- 6 years) were enrolled in the study. In each patient left atrial (LA) thrombus was excluded by transesophageal echocardiography. sP-selectin levels were compared between study patients and controls, and between peripheral and LA blood. Changes in sP-selectin level 24 h and 4 weeks after PMBV were also analyzed. RESULTS: A significantly higher basal sP-selectin level was noted in study group. After PMBV, the mitral valve area (MVA) increased and the transmitral mean gradient decreased significantly. At 24th hour after PMBV, sP-selectin level decreased from 1080.38 +/- 143.87 ng/ml to 960.00 +/- 103.26 ng/ml (p < 0.0001) and at 4th-week follow-up it was decreased from 960.00 +/- 103.26 ng/ml to 879.61 +/- 98.16 ng/ml (p < 0.0001). No significant difference was found between peripheral and LA blood regarding the sP-selectin level. Correlation analysis between the difference in MVA measured 24-hour after and before PMBV and the difference in sP-selectin level measured 24-hour after and before PMBV showed a significant direct relationship between these variables. CONCLUSION: This study suggests that in patients with MS and sinus rhythm sP-selectin level increases probably due to turbulent flow across the stenotic valve. After PMBV sP-selectin shows a progessive decline, which is directly correlated with the increase in MVA.

Relation between sympathetic overactivity and left atrial spontaneous echo contrast in patients with mitral stenosis and sinus rhythm.

BACKGROUND: Spontaneous echo contrast (SEC) is common in patients with mitral stenosis (MS) and presence of SEC in left atrium (LA) is associated with a higher risk of thromboembolism. Recently, an increase in activation of platelets was demonstrated in patients with SEC raising the hypothesis that platelets are involved in the pathogenesis of SEC. In this study, we evaluated effects of autonomic nervous system activity on SEC formation in patients with rheumatic MS and sinus rhythm by heart rate variability analysis. METHODS AND RESULTS: Twenty-six patients with LASEC were compared with 28 patients without LASEC. Mean heart rate, low frequency (LF) and low frequency/high frequency (LF/HF) ratio were significantly higher, standard deviation of all NN (SDNN), root mean square of successive differences (RMSSD), number of NN intervals that differed by more than 50 ms from adjacent interval divided by the total number of all NN intervals (PNN50) and high frequency (HF) values were lower in the patients with LASEC. A standard deviation of all NN intervals <90ms separated the patients with LASEC from control subjects with a sensitivity of 77% and specificity of 90%; a low frequency >79.5 with a sensitivity of 92% and specificity of 90; a low frequency/high frequency ratio >3.7 with a sensitivity of 96% and specificity of 90%. A left atrial diameter >4.3 cm increased the LASEC formation by 3.0 folds, HR >78 beats/min by 6.4 folds, standard deviation of all NN intervals <90 ms by 9.2 folds, a low frequency/high frequency ratio >3.7 by 6.4 folds, sP-selectin>142 by 5.8 folds. Variables affecting sP-selectin levels were LA diameter, mitral valve area, transmitral mean gradient, left ventricular ejection fraction, the presence of mitral regurgitation, HR, standard deviation of all NN intervals, low frequency, high frequency and low frequency/high frequency ratio. CONCLUSION: Sympathetic overactivity and reduced heart rate variability are important determinants for LASEC formation and increased s-P selectin levels. Therefore, platelet activation via increased sympathetic activity may play an important role in pathogenesis of LASEC.

Myocardial injury due to lightning strike--a case report.

Lightning strike is a natural phenomenon with potentially devastating effects and represents one of the leading causes of cardiac arrest and death from environmental phenomena. Almost every organ system may be impaired as lightning passes through the human body taking the shortest pathways between the contact points. In this paper, the authors report a 38-year-old man who was injured by lightning, a typical example of ;;side splash,'' and had transient electrocardiographic changes.

Serum level of lipoprotein (a) is inversely associated with the development of coronary collateral circulation.

BACKGROUND: This study sought to determine the relationship between serum lipoprotein (a) levels and angiographically visible coronary collateral circulation and to evaluate whether lipoprotein (a) exerts any effect on vascular endothelial cell growth factor. METHODS: The study population included 60 patients (39 men, mean age 59+/-13 years) with angiographically documented total occlusion in one of the major coronary arteries. Development of collaterals was classified by Rentrop's method. Patients were defined as having poorly developed collaterals for grades 0 and 1 (group 1), or well-developed collaterals for grades 2 and 3 (group 2). Serum lipoprotein (a) and vascular endothelial cell growth factor levels were determined by enzyme-linked immunosorbent assay. RESULTS: In group 1, lipoprotein (a) levels were significantly higher and vascular endothelial cell growth factor levels were significantly lower than in group 2 (34+/-19 vs. 20+/-12 mg/dl, P<0.001, and 2.5+/-0.7 vs. 3.4+/-0.8 ng/dl, P<0.001, respectively). Poorly developed collaterals were significantly more frequent in patients with lipoprotein (a) levels >or=30 mg/dl than in patients with levels <30 mg/dl (72 vs. 37%, P=0.008). A strong negative correlation was observed between lipoprotein (a) and vascular endothelial cell growth, factor (r=-0.708, P<0.0001). Multivariate analysis revealed that a high level of lipoprotein (a) negatively affected the development of collaterals, whereas the duration of angina had a positive effect. CONCLUSION: This study demonstrated for the first time that the high level of lipoprotein (a) negatively affects the formation of coronary collateral vessels in human beings. Reduced production or bioactivity of vascular endothelial cell growth factor caused by high levels of lipoprotein (a) may be the possible responsible mechanisms of hyperlipoprotein (a)-related poor collateral formation.

Does p-wave dispersion predict the atrial fibrillation occurrence after direct-current shock therapy?

Supraventricular tachycardia attacks, including atrial fibrillation (AF), occur after both external and internal cardioversions. These attacks of atrial fibrillation after direct-current (DC) shock may be related to hemodynamic impairment, thromboembolic events, or enhanced electrical instability of the ventricular and atrial myocardium, especially in predisposed patients. In this study, the authors aimed to show the importance of P-wave dispersion (PWD), which lead the atrium to fibrillate, in predicting post-DC shock AF after external cardioversion. Thus physicians may be able to choose the patients with high risk for AF occurrence and apply some other therapeutic modalities to those patients. The authors identified 18 patients in whom an AF attack was induced by urgent or elective cardioversion for a ventricular tachycardia attack and compared these patients with a control group composed of 40 patients without AF in regard to some clinical, echocardiographic, and electrocardiographic parameters. Left atrial diameters were greater (4.3+/-0.3 vs 3.5+/-0.5 cm, p = 0.001), left ventricular ejection fractions (LVEF) were lower (45.2+/-8.2 vs 54.9+/-7.5, p = 0.001), the energy needed for successful cardioversion was higher (166.6+/-59.4 vs 80.8+/-51.6 J, p = 0.001), and P max (135.2+/-7.4 vs 118.7+/-10.5 ms, p = 0.001) and PWD (53.8+/-12.2 vs 23.8+/-9.5 ms, p = 0.001) values were higher in patients with AF when compared to those without AF. Thus, the patients with higher PWD values had a greater risk for development of AF after a DC shock.

Single coronary artery presenting with cardiogenic shock due to acute myocardial infarction.

Percutaneous coronary revascularization plays an important role in the management of acute coronary syndrome. Unpredictable angiographic findings of anomalous coronary arteries may, however, compromise the otherwise high and predictable success rates of this intervention. We report a case of failed coronary angioplasty of the left anterior descending artery through an anomalous left main coronary artery originating from the right coronary sinus in a 33-year-old man with acute myocardial infarction complicated by cardiogenic shock. Subsequently the patient performed successful emergency coronary artery bypass graft.

Giant Left Anterior Descending Artery Aneurysm in a Patient with Behcet's Disease.

Coronary artery aneurysm is a rare coronary abnormality nearly half of which originates from atherosclerotic lesions. The major causes of non-atherosclerotic coronary aneurysms include coronary ectasia, Kawasaki disease, Takayasu aortitis, thoracic trauma and complicated angioplasty; however, it has been rarely reported associated with Behcet's disease.

Collaterals that regressed after angioplasty can be recruited to protect the left ventricle in case of an acute occlusion.

A considerable fraction of collaterals has been shown to regress immediately after percutaneous transluminal coronary angioplasty (PTCA), but the fate of these well-developed collaterals is unknown. The authors aimed to show the protective role of these recruitable collaterals in case of an acute myocardial infarction (MI). They identified 22 patients who underwent PTCA and then were rehospitalized owing to acute myocardial infarction. These patients were compared with a group consisting of 48 patients hospitalized owing to acute MI without a history of previous PTCA. Then, the patients with collaterals were compared with the patients without collaterals to define the factors affecting the collateral formation. All the patients with collaterals before PTCA were shown to have collaterals also after AMI, and collateral grades were greater after MI (1.67 +/-0.98) when compared with those before PTCA (0.73 +/-0.7) (p = 0.001). Coronary collaterals were more commonly seen in patients with a history of previous PTCA (p = 0.005), and the grades of collaterals were also higher in these patients when compared with those without PTCA. Left ventricle score indices were lower and left ventricular ejection fractions (LVEF) were higher in patients with a history of PTCA (p = 0.001). Logistic regression analysis revealed that smoking increased the development of collaterals after AMI 3.8 fold, aspirin use 4.1 fold. On the contrary, diabetes mellitus (DM) decreased this 6.67 fold. As a result, well-developed coronary collaterals are preserved even if they have regressed after restoration of flow, and they may become functional and protect the myocardium against acute ischemia.