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.

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.

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.

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.

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.

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.

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.

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.

Effects of previously well-developed collateral vessels on left internal mammary artery graft flow after bypass surgery.

Transthoracic Doppler ultrasonography can assess left internal mammary artery patency and flow after coronary artery bypass grafting. We aimed to show, by transthoracic Doppler ultrasonography, the early effects upon left internal mammary artery graft flow of preoperative collateral vessels supplying the left anterior descending artery. Thirty-four consecutive patients undergoing coronary artery bypass were prospectively enrolled: 19 patients with collateral vessels supplying the left anterior descending were compared with 15 patients without collaterals. After bypass, end-diastolic velocity, mean velocity, flow volume, and ejection fraction were significantly greater, and the resistivity index was lower in patients with collateral vessels. The changes in velocities, volume, resistivity index, and pulsatility index were also found to be greater in patients with collateral vessels than in those without collaterals. Collateral vessels were the only factor affecting the changes in end-diastolic volume, mean velocity, flow volume, and resistivity index in multivariate analysis. Three factors affected postoperative left ventricular ejection fraction: collateral vessels, preoperative ejection fraction, and changes in left internal mammary flow volume. We conclude that patients with well-developed collaterals to the left anterior descending have better flow in the left internal mammary graft and more significant improvement in left ventricular function after coronary bypass. The flow volume of the mammary graft and the improvement of ventricular systolic functions after coronary bypass might be presumed with the presence of grade 2 or 3 preoperative collateral vessels.

Brugada-type electrocardiographic pattern induced by fever.

ST-segment elevation in Brugada syndrome is caused by a shift in the ionic current balance and the creation of a voltage gradient between the epicardium and the endocardium. This ionic mechanism have been shown to be temperature dependent. We describe a 33-year-old man who presented with fever with the dynamic electrocardiographic changes similar to the Brugada syndrome. These electrocardiographic anomalies disappeared when the temperature returned to normal.

Polymyositis complicated with complete atrioventricular block--a case report and review of the literature.

A 35-year-old woman, diagnosed with polymyositis about 5 years before was admitted to the authors' clinics with syncope attack due to complete atrioventricular (AV) block. Progression of left bundle branch block to complete AV block despite all immune-suppressive treatment, and rarity of this complication in patients with polymyositis prompted the authors to report this case.

Increased sympathetic nervous system activity as cause of exercise-induced ventricular tachycardia in patients with normal coronary arteries.

In this prospective study, we set out to determine whether analysis of heart rate variability (HRV) in patients with exercise-induced ventricular tachycardia (EIVT) and normal coronary arteries would reveal increased sympathetic nervous system activity. From January 1996 to December 2001, we compared 16 patients with EIVT and normal coronary arteries with an age- and sex-matched control group. Analysis of HRV showed that parameters indicative of parasympathetic activity were lower in our study group than in our control group: standard deviation of the mean of qualified NN intervals (SDNN), 81.6 +/- 14.5 vs 139.3 +/- 11.0, P <0.001; root mean square of successive differences (RMSSD), 22.3 +/- 4.8 vs 36.3 +/- 6.6, P <0.001; number of NN intervals that differed by more than 5 ms from the adjacent interval, divided by the total number of NN intervals (PNN50), 4.8 +/- 1.5 vs 10.2 +/- 3. 1, P <0.001; and high-frequency component (HF), 28.7 +/- 2.5 vs 32.4 +/- 3.9, P <0.05. Conversely, parameters indicative of sympathetic activity were higher in patients with EIVT: low-frequency component (LF), 71.2 +/- 5.0 vs 52.0 +/- 5.8, P <0.001; and absolute low/high frequency component ratio (LF/HF), 2.7 +/- 0.2 vs 1.6 +/- 0.2, P <0.001. There was a positive correlation between EIVT and LF (r=0.79, P <0.001) and between EIVT and LF/HF (r=0.81, P <0.001). Our results suggest the presence of increased sympathetic and decreased parasympathetic tone in patients with EIVT. We conclude that EIVT is associated with an imbalance in the autonomic nervous system.

Association between mean platelet volume and autonomic nervous system functions: Increased mean platelet volume reflects sympathetic overactivity.

BACKGROUND: Increased mean platelet volume (MPV) may reflect increased platelet activation or increased numbers of large, hyperaggregable platelets, and is accepted as an independent coronary risk factor. The adrenergic system has effects on platelet activation and thrombocytopoiesis. OBJECTIVE: To assess the effects of autonomic nervous system activity on MPV in patients with acute myocardial infarction (MI). METHODS AND RESULTS: Forty-seven patients with acute anterior MI were compared with 32 patients with healthy coronary arteries. All patients underwent heart rate (HR) variability analysis using 24 h Holter monitoring. Blood samples were taken for MPV measurements twice a day (day- and nighttime) during Holter monitoring. Mean HR, low frequency band of HR variability power spectrum to high frequency band of HR variability power spectrum (LF:HF) ratio, LF and MPV were higher in patients with anterior MI than in the control group. SD of all NN (RR) intervals, root mean square of successive differences, number of NN intervals that differed by more than 50 ms from the adjacent interval divided by the total number of all NN intervals, HF bands and platelet counts were lower in the patients with anterior MI than in the control group. Daytime LF bands, LF:HF ratio and MPV were significantly higher, and HF bands were significantly lower than the nighttime values for both groups. The differences in daytime and nighttime measurements were more significant in the patients with acute MI than in the control group. Pearson's correlation analysis showed that MPV was positively correlated with ventricle score, degree of left anterior descending artery stenosis, mean HR, LF bands and LF:HF ratio; and negatively correlated with the SD of all NN intervals, HF bands and platelet count. Multivariate analysis revealed that MPV was significantly affected by ventricle score and the LF:HF ratio. CONCLUSIONS: MPV was significantly higher in the patients with acute MI. In both groups, MPV showed great daytime and nighttime variation, which can be attributed to alterations in the autonomic nervous system. The authors suggest that the prognostic role of increased MPV in patients with acute MI is closely associated with increased sympathetic activity and decreased HR variability.

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.