Myocardial Injury Due to Lightning Strike

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.

Polymyositis Complicated with Complete Atrioventricular Block

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.

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.

Right ventricular outflow tract function in chronic obstructive pulmonary disease

BACKGROUND

It is clinically important to evaluate the severity of right ventricular (RV) overload in patients with chronic obstructive pulmonary disease (COPD), which is often associated with changes in the structure and the function of the right ventricle. Noninvasive and reliable assessment of RV function would be an essential determinant of RV load and a clinically useful factor for assessing cardiovascular risk in COPD patients.

OBJECTIVE

The aim of this study was to investigate the clinical application value of right ventricular outflow tract (RVOT) systolic function measured by transthoracic echocardiography in patients with COPD.

PATIENTS AND METHODS

We prospectively investigated COPD male patients and compared them with healthy controls. In addition to RV conventional echocardiographic parameters, RVOT size and fractional shortening (RVOT-FS) parameters were also assessed.

RESULTS

Fifty-five COPD patients (all men; mean age, 62 ± 9 years) participated in the study, and were compared with a control group consisting of 21male, healthy, nonsmoking subjects with a mean age of 58 ± 11 years. The RVOT-FS was impaired in COPD patients than healthy controls (27.8 ± 15.5 vs. 57.5 ± 8.6, p < 0.001), and was correlated positively with tricuspid annular plane systolic excursion (TAPSE; r = 0.583, p < 0.001) and pulmonary acceleration time (r = 0.666, p < 0.001) and inversely with pulmonary artery systolic pressure (r = 0.605, p < 0.001) and functional capacity(r = - 0.589, p < 0.001). There was a statistically significant difference in RVOT-FS among the COPD subgroups with regard to New York Heart Association functional classification (p < 0.001).

CONCLUSION

The RVOT-FS is a noninvasive easily applicable measure of RV systolic function and is well correlated with functional capacity in COPD patients. Its combination with long-axis measurements via TAPSE and transtricuspid Doppler analysis may provide a comprehensive evaluation of the RV performance in COPD patients.

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.

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.

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.

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.

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.

Aortic dissection with diastolic prolapse of intimal flap into left ventricle

Ascending aortic dissection is often a catastrophic condition. Dissection into the commissures or into an aortic valve leaflet may lead to leaflet avulsion and valvular insufficiency due to a flail valve. We present an image report describing an important and life-threatening complication due to the movement of a partially dehisced intimal aortic flap into the left ventricle causing aortic valve insufficiency in a patient with acute dissection of the ascending aorta.

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.

Improvement in sympatho-vagal imbalance and heart rate variability in patients with mitral stenosis after percutaneous balloon commissurotomy

Elevated sympathetic nerve activity in patients with mitral stenosis (MS) may be an index of the severity of the disease. Percutaneous mitral balloon commissurotomy (PMBC) is now a standard treatment for many patients with symptomatic MS. We aimed to show the effects of PMBC on autonomic nervous system activity in the patients with MS by heart rate variability (HRV) analysis. Fifty-four consecutive patients with mitral stenosis and sinus rhythm who underwent percutaneous mitral commissurotomy were enrolled. Apart from significant haemodynamic improvements, mean heart rate (HR), LF day, LF night, LF/HF day and night significantly decreased and SDNN, RMSSD, PNN50, HF day and night significantly increased in the early period after PMBC and these changes were preserved for up to one month. SDNN was positively correlated with left ventricle ejection fraction (LVEF) but negatively correlated with mean valve area (MVA), left atrial (LA) diameter and pressure, right atrial (RA) pressure; LF/HF day ratio was positively correlated with LA diameter and pressure, mean transmitral gradient and negatively correlated with LVEF; LF/HF night ratio was positively correlated with LA pressure and mean transmitral gradient. The increase in SDNN was correlated with the change in LA and RA pressure. The decrease in LF/HF ratio after PMBC was significantly correlated with the changes in the mean transmitral gradient, LA pressure and RA pressure. As a result, the heart rate variability and autonomic nervous system function in patients with mitral stenosis are correlated with the atrial pressures and left ventricular function. These parameters significantly change in the early period after PMBC and are preserved at one month. The improvement in the heart rate variability and sympatho-vagal balance are significantly affected by the early changes in atrial pressures after PMBC.

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.

Sympathetic overactivity in patients with rheumatic mitral stenosis

BACKGROUND

Mitral stenosis may increase sympathetic nervous activity by increasing left atrial pressure and reducing cardiac output. And elevated sympathetic nerve activity may be a risk factor for the development of clinical manifestations of mitral stenosis. In this study, we assessed the autonomic nervous system activity in patients with mitral stenosis by heart rate variability analysis and defined factors affecting autonomic functions.

METHODS AND RESULTS

Fifty-four patients with rheumatic mitral stenosis were compared with an age- and gender-matched control group composed of 42 healthy individuals. SDNN, RMSSD, PNN50, and HF were lower; mean heart rate (HR), LF and LF/HF ratio were higher in the patients with mitral stenosis compared to the control group. SDNN was correlated positively with left ventricle ejection fraction (LVEF), negatively with mitral valve area, left atrial (LA) diameter, and duration of symptoms. RMSSD was correlated positively with mean transmitral gradient, negatively correlated with age; PNN50 was correlated negatively with mitral valve area and positively correlated with transmitral gradient. LF was positively and HF was negatively correlated with LA diameter; LF was correlated positively, and HF was negatively correlated with duration of symptoms. LF/HF ratio was positively correlated with LA diameter and duration of symptoms, negatively with LVEF and mean valve area.

CONCLUSION

As a result, sympathetic nervous system activity is increased in patients with mitral stenosis and sympathetic overactivity worsens their symptoms. Most significant factors that affect autonomic functions in these patients are left atrial dilatation and mitral valve area.

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.

Evaluation of the Early Hemodynamic Changes in Carotid Arteries During Ventricular and Dual Chamber Pacing

In spite of a wide choice of pacemakers, there are some problems in making more rational clinical decisions for individual patients since mode selection and programming is usually performed on the basis of a clinical hunch. The aim of this study was to measure the differences in carotid flow in patients with a pacemaker programmed in the dual chamber and in the single chamber pacing modes. Sixty patients with implanted bipolar DDD pacemakers were enrolled in this study. Blood peak systolic velocity (PSV) and end-diastolic velocity (EDV), cross-sectional area, resistive index (RI), and pulsatility index (PI) were measured in the common (CCA), internal (ICA), and external (ECA) carotid arteries before pacemaker implantation and after dual chamber and ventricular pacing at 60 beats/min. PSVs in the left CCA (79.3 +/- 24.9 cm/s) and right CCA (84.1 +/- 18.7) were shown to significantly decrease after VVI pacing (60.1 +/- 16.6 and 62.1 +/- 20.0, respectively). There was also a similar significant decrease in PSV in the left and right ICAs and ECAs. Besides PSV, RI, and PI in the left and right CCAs, ICAs, and ECAs significantly decreased after VVI pacing. There was no similar decrease after DDD pacing. Cross-sectional area and flow volume in the CCA, ICA, and ECA were similar after DDD and VVI pacing and before pacemaker implantation suggesting that cardiac output was similar when the measurements were recorded. Carotid artery PSVs, pulsatility, and RIs were found to be significantly decreased during VVI pacing compared to baseline and DDD pacing. The greater incidence of adverse cerebral outcomes in patients with VVI rather than DDD pacing may be partly due to decreased carotid PSVs.

Does claudication affect the development of coronary collaterals?

Atherothrombosis is a generalized disease process that affects large- and medium-diameter arteries throughout the arterial tree. In this study, we aimed to evaluate the correlation between collaterals in different vascular beds. Patients who had undergone digital subtraction angiography for symptomatic lower extremity peripheral arterial disease and coronary angiography after an acute anterior myocardial infarction (MI) were compared with a control group composed of those patients who were hospitalized for acute anterior MI and underwent coronary angiography but had no claudication and had an ankle-brachial index of greater than 0.9 in both legs. In claudicants, stenosis in the left anterior descending artery (LAD) (90.3 +/- 17.5 vs 78.6 +/- 13.8, P = 0.005) was greater compared with the patients without claudication. The collaterals to the LAD (88% vs 37.5%, P = 0.001) and the collateral grades (1.7 +/- 0.7 vs 0.7 +/- 0.9, P = 0.001) were higher in the patients with claudication compared with those without claudication. A previous history of angina (52.2% vs 16.3%, P = 0.001), claudication (39.1% vs 4.6%, P = 0.001), and peripheral collaterals (45.7% vs 6.9%, P = 0.001) were higher in the patients with coronary collaterals than in those without. The factors affecting the development of coronary collaterals were claudication [relative risk (RR): 8.8; 95% confidence interval (CI): 2.1-39.8], peripheral collaterals (RR: 1.1; 95% CI: 1.1-1.3), and LAD stenosis (RR: 1.2; 95% CI: 0.03-29.1). Our results suggest that the presence of collateralization or angiogenesis in one vascular bed highly predicts collateralization in another arterial bed.

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.

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.