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.

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.

Traumatic type B aortic dissection causing near total occlusion of aortic lumen and diagnosed by transthoracic echocardiography: A case report.

A true dissection of the descending thoracic aorta resulting from blunt chest trauma is a relatively rare injury compared with aortic transsection and occurs mostly in the region of the aortic isthmus. It is a life-threatening condition that requires rapid and accurate diagnosis. In this case, we report a patient with Stanford type B aortic dissection caused by decelerating trauma of the chest in a motor vehicle accident causing near total occlusion of the aortic lumen. The diagnosis was made by transthoracic echocardiography and confirmed by aortography.

Poor coronary collateral circulation is associated with higher concentrations of soluble adhesion molecules in patients with single-vessel disease.

OBJECTIVE: As the endothelium and inflammatory cells play a crucial role in the development of collaterals after a sudden or slowly progressing stenosis of coronary arteries, the levels of soluble endothelial adhesion molecules (CAMs) including vascular cell adhesion molecule (VCAM-1) intercellular adhesion molecule-1 (ICAM-1) and E-selectin were compared between patients with poor coronary collaterals and patients with well-developed collaterals. METHODS: In the study, 97 non-diabetic subjects with single-vessel disease were included. Collateral supply to the stenotic coronary artery was determined by angiographic grading system of 0-3 (Rentrop et al. J Am Coll Cardiol 1985; 5:587-592). Serum levels of adhesion molecules were measured by enzyme-linked immunosorbent assay. RESULTS: Patients were divided into two groups according to the collateral degree (group A: 50 patients with grade 0 and 1; group B: 47 patients with grade 2 and 3 collaterals). The groups were well matched with respect to baseline clinical and angiographic characteristics. Levels of soluble VCAM-1 (mean+/-SEM; 875+/-26.6 versus 742.7+/-35.1 ng/ml; P=0.004), ICAM-1 (322.4+/-12.4 versus 269.4+/-13.3 ng/ml; P=0.005), and E-selectin (43.6+/-2.6 versus 33+/-2.4 ng/ml; P=0.004) were found to be significantly higher in group A in comparison with group B. In addition, when patients were divided into four groups according to the collateral degree, patients with grade 0 collaterals had the highest values and those with grade 3 collaterals had the lowest values for all these molecules. CONCLUSIONS: We concluded that poor collateral circulation is associated with increased levels of soluble CAMs in patients with obstructive coronary artery disease. However, further studies are needed to elucidate the exact role of these inflammatory markers in the setting of poor collateral circulation.

Left ventricular aneurysm formation after anterior myocardial infarction: clinical and angiographic determinants in 809 patients.

BACKGROUND: Previous studies have reported controversial results regarding the clinical and angiographic factors involved in the left ventricular aneurysm (LVA) formation after myocardial infarction (MI). OBJECTIVE: This study was performed to determine the clinical and angiographic factors that are priori predictors of LVA following anterior myocardial infarction and so to provide a paradigm which may identify patients who were candidates for aneurysm formation. METHODS: Of the patients who underwent coronary angiography during the interval between 1995 and 2000 in our clinic, 809 were found to have anterior MI and LVA (aneurysm group) (677 men, 132 women, mean age 53.3+/-11.4 years). The clinical and the angiographic data of these patients were compared with those of 446 patients (399 men, 47 women, mean age 55.2+/-10.5 years) with previous anterior MI and without LVA (control group). RESULTS: LVA was found to occur more frequently in females (16.3% in women and 10.4%, in men, P=0.03) and in patients without previous angina (23.5 vs. 8.2%, P<0.0001). Major cardiovascular risk factors, previous anti-anginal medication and thrombolytic therapy did not show a significant difference between the two groups. Angiographic examination revealed that single-vessel disease, proximal left anterior descending artery (LAD) stenosis, total LAD occlusion, mean stenosis in LAD artery, end-diastolic pressure and left ventricular score were all higher in the aneurysm group compared to control group. After adjustment for other clinical and angiographic variables, single-vessel disease [odds ratio (OR) 5.89, 95% confidence interval (CI)=3.68-9.28, P<0.0001), absence of previous angina (OR=4.21, 95% CI=2.1-7.48, P=0.0003), total LAD occlusion (OR=2.63, 95% CI=1.97-3.53, P<0.0017) and female gender (OR=1.60, 95% CI=1.20-2.28, P=0.043) remained the independent determinants of LVA formation after anterior MI. CONCLUSION: In patients with LVA, logistic regression analysis revealed that (1) single-vessel disease, (2) absence of previous angina, (3) total LAD occlusion and (4) female gender were independent determinants in the formation of LVA after anterior MI. Coronary collateral status and risk factors, such as hypertension, diabetes mellitus, hypercholesterolemia, smoking and family history of CAD were not found to be important determinants in the aneurysm formation.

Evaluation of P wave duration and P wave dispersion in adult patients with secundum atrial septal defect during normal sinus rhythm.

BACKGROUND: Paroxysmal atrial arrhythmias especially atrial fibrillation (AF) are frequently encountered in adult patients with atrial septal defect (ASD). Previously it was shown that maximum P wave duration and P wave dispersion in 12-lead surface electrocardiograms are significantly increased in individuals with a history of paroxysmal AF. The aim of this study was to determine whether P maximum and P dispersion in adult patients with ASD and without AF are increased as compared to healthy controls. In addition, the relationship of pulmonary to systemic flow ratio (Qp/Qs) and these P wave indices were investigated. METHODS AND RESULTS: Sixty-two consecutive patients [39 women, 23 men; mean age 33+/-13 years (range 16 to 61 years)] with ostium secundum type ASD and 47 healthy subjects [25 women, 22 men; mean age 36.6+/-9.5 years (range 18 to 50 years)] were investigated. P maximum, P minimum and P dispersion (maximum minus minimum P wave duration) were measured from the 12-lead surface ECG. There were no significant differences with respect to age (P=0.08), gender (P=0.3), heart rate (P=0.3), left atrial diameter (P=0.5) and left ventricular ejection fraction (P=0.3) between patients and controls. Pulmonary artery peak systolic pressure was significantly higher in patients with ASD as compared to controls (P<0.0001). P maximum was significantly longer in patients with ASD as compared to controls (P<0.0001). In addition, P dispersion of the patients was significantly higher than controls (P=0.001). P minimum was not different between groups (P=0.12). Mean Qp/Qs of the patients with ASD was 2.5+/-0.7 (minimum 1.5; maximum 4.1) and found to be significantly correlated with P maximum (r=0.34; P=0.006) and P dispersion (r=0.61; P<0.0001). CONCLUSIONS: Prolongation of P maximum and increased P dispersion could represent mechanical and electrical changes of atrial myocardium in patients with ASD. These changes of atrial myocardium may be more prominent with higher left to right shunt volumes.

P-wave durations as a predictor for atrial fibrillation development in patients with hypertrophic cardiomyopathy.

Atrial fibrillation (AF) is the most common arrhythmia observed in hypertropic cardiomyopathy (HCM) and is associated with an acute deterioration. Recently, P wave dispersion (PWD) reflecting inhomogeneous atrial conduction has been proposed as being useful for the estimation of paroxysmal AF. In this study, we aimed to define the clinical, echocardiographic and electrocardiographic predictors for AF occurrence in patients with HCM. Twenty-seven patients diagnosed with HCM and having a history of documented AF attack were compared with 53 age- and gender-matched patients who had no such history. LA diameter was significantly greater and gradient in the left ventricle outflow tract was lower in patients with AF than those without AF. Maximum P-wave duration (Pmax), PWD and PTF1 values were significantly higher in patients with AF. A Pmax>134.5 ms separated the patients with AF from controls with a sensitivity of 92%, specificity of 89% and a positive predictive value of 80%. APWD value>52.5 ms separated patients from controls with a sensitivity of 96%, a specificity of 91% and a positive predictive accuracy of 84%. An LA diameter>4.2 cm separated patients from controls with a sensitivity of 96% and a specificity of 81%. We concluded that LA diameter and PWD values are the most significant predictors for AF occurrence in patients with HCM, and simply by measuring Pmax and PWD values, we could easily identify the patients with high risk, and prescribe the necessary treatment and follow-up protocols for such patients.

Levels of soluble adhesion molecules in various clinical presentations of coronary atherosclerosis.

Adhesion molecules play an important role in the development and course of coronary atherosclerosis. In this study, soluble forms of vascular cell adhesion molecule (VCAM-1) intercellular adhesion molecule-1 (ICAM-1), E-selectin and P-selectin were evaluated in patients with various clinical presentations of coronary atherosclerosis and compared them to those with angiographically documented normal coronary arteries. Venous plasma samples were collected from 43 patients with acute myocardial infarction (AMI), 45 with unstable angina pectoris (UAP), 34 with stable angina pectoris (SAP) and 29 subjects with normal coronary arteries (control). The VCAM-1 level was significantly higher in patients with AMI (mean +/- SEM; 799.8 +/- 26.3 ng/ml) than those with UAP (644.2 +/- 26.7 ng/ml) and SAP (526 +/- 32.5 ng/ml) and controls (270 +/- 26.8 ng/ml). In patients with UAP, VCAM-1 was found to be significantly elevated as compared to the SAP group and controls. VCAM-1 level was also higher in SAP group than the controls. Serum levels ICAM-1 were similar among patients with AMI (424.1 +/- 15.2 ng/ml), UAP (403 +/- 12.3 ng/ml) and SAP (381.2 +/- 16.2 ng/ml); however, levels of ICAM-1 was significantly elevated in these groups as compared to the controls (244.3 +/- 11). The mean level of E-selectin was not different in AMI and UAP groups (47.2 +/- 2.2 vs. 42.6 +/- 2.1 ng/ml; respectively). However, it was significantly higher in acute coronary syndrome groups as compared to SAP (33.4 +/- 2.3 ng/ml) and control subjects (30.7 +/- 1.9 ng/ml). Serum levels of E-selectin were similar in SAP group and controls. For P-selectin, no significant difference was observed between AMI and UAP groups (187.5 +/- 7.2 vs. 181.7 +/- 4.7 ng/ml; respectively), however, it was significantly higher in both groups as compared to SAP group (146.1 +/- 7.4 ng/ml) and controls (108 +/- 6.6 ng/ml). Serum level of P-selectin was significantly higher in patients with SAP than the control group. In conclusion, determination of serum VCAM-1, E-selectin and P-selectin levels seems more useful for detecting coronary plaque destabilization.

Diabetes mellitus adversely affects the outcomes of thrombolytic therapy in patients with acute myocardial infarction.

This study was performed to evaluate whether coexistent diabetes mellitus has any adverse effect on the outcomes of thrombolytic therapy in patients with acute myocardial infarction. Although the early reperfusion rates were similar between the two groups of patients who had acute myocardial infarction with and without diabetes mellitus (42% vs 45.4%, p > 0.05), the results of late angiographic examination showed a significantly lower rate of patency in infarct-related coronary artery (defined as TIMI 3 flow) in diabetics compared to nondiabetics (28.9% vs 41.3%, p < 0.001). The global left ventricular function was also poorer in diabetics (left ventricular wall motion score was 18.6 +/- 7.3 in diabetics and 14.1 +/- 4.6 in nondiabetics, p < 0.01).

An unusual primary left ventricular hydatid cyst complicated by cardiac tamponade and mitral regurgitation--a case report.

Cardiac involvement in hydatidosis is rare but because of potentially lethal complications, its recognition is of great importance. The authors present a 55-year-old woman admitted to the clinic with cardiac tamponade and moderate mitral regurgitation caused by a hydatid cyst located at the inferoposterior wall of the left ventricle.

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.

Increased p-wave duration and p-wave dispersion in patients with aortic stenosis.

BACKGROUND: P-wave dispersion (PWD), defined as the difference between the maximum and minimum P-wave duration, has been proposed as being useful for the prediction of paroxysmal atrial fibrillation (AF). AF is the most common arrhythmia and an important prognostic indicator for clinical deterioration in patients with aortic stenosis (AS). The aim of the present study was to evaluate PWD in patients with AS. METHODS: The study population consisted of two groups: Group I consisted of 98 patients with AS (76 men, 22 women; aged 63 +/- 8 years) and group II consisted of 98 healthy subjects (same age and sex) without any cardiovascular disease. A 12-lead electrocardiogram was recorded for each subject. The P-wave duration was calculated in all leads of the surface electrocardiogram. The difference between the maximum and minimum P-wave duration was calculated and was defined as the PWD. All patients and control subjects were also evaluated by echocardiography to measure the left atrial diameter, left ventricular ejection fraction, left ventricular wall thicknesses, and the maximum and mean aortic gradients. Patients were also evaluated for the presence of paroxysmal AF. RESULTS: Maximum P-wave duration and PWD of group I were found to be significantly higher than those of group II. In addition, patients with paroxysmal AF had significantly higher PWD than those without paroxysmal AF. There was no significant difference between the two groups regarding minimum P-wave duration. In addition, there was no significant correlation between echocardiographic variables and PWD. CONCLUSION: PWD, indicating increased risk for paroxysmal AF, was found to be significantly higher in patients with AS than in those without it. Further assessment of the clinical utility of PWD for the prediction of paroxysmal AF in patients with severe AS will require longer prospective studies.

Diagnostic value of aVL derivation for right ventricular involvement in patients with acute inferior myocardial infarction.

BACKGROUND: Right ventricular (RV) involvement is associated with increased morbidity and mortality in patients with acute inferior myocardial infarction (MI). Although electrocardiography is probably the most useful, simple, and objective tool for the diagnosis of acute MI, there are no well-defined criteria in the standard 12-lead electrocardiogram to properly identify RV involvement in patients with acute inferior MI. Our objective was to evaluate the value of ST-segment depression in lead aVL in diagnosing RV involvement in patients with acute inferior MI. MATERIALS AND METHODS: Sixty-seven patients, hospitalized with acute inferior myocardial infarction, were included in this study. The diagnosis of acute inferior myocardial infarction was based on the clinical history, characteristic enzyme pattern of CK-MB values, and the appearance of ST-segment elevation > or = 1 mm in at least two of the leads (leads II, III, aVF). RV infarction was defined by ST-segment elevation > or = 1mm in lead V4R. ST-segment depression in lead aVL that is more than 1 mm was accepted as a diagnostic criterion for RV involvement in patients with acute inferior MI. RESULTS: Thirty-one patients had >1 mm ST-segment depression and 28 of them had right ventricular infarction according to lead V4R. Thirty-six patients showed < or =1 mm ST-segment depression indicating no right ventricular involvement but four of them also had right ventricular infarction according to V4R. CONCLUSION: More than 1 mm ST-segment depression in lead aVL was found to have high sensitivity (87%), specificity (91%), high positive and negative predictive value (90%, 88%, respectively), and high diagnostic accuracy (89%) in diagnosing RV involvement in patients with acute inferior MI. Therefore, by using a simple 12-lead electrocardiographic sign, ST-segment depression >1 mm in lead aVL, obtained on admission, it is possible to identify RV involvement in patients with acute inferior MI.

Effects of slow coronary artery flow on QT interval duration and dispersion.

BACKGROUND: The coronary slow-flow phenomenon is an angiographic phenomenon characterized by delayed opacification of vessels in the absence of any evidence of obstructive epicardial coronary disease. Several studies have demonstrated myocardial ischemia in patients with slow coronary artery flow. In the present study, we aimed at evaluating the effects of slow coronary artery flow on QT interval duration and QT dispersion as a possible indicator of increased risk for ventricular arrhythmias and sudden cardiac death. METHODS: The study population included 49 patients with angiographically proven normal coronary arteries and slow coronary flow in all three coronary vessels (group I, 33 males, 16 females, mean age = 48 +/- 9 years), and 71 patients with angiographically proven normal coronary arteries without associated slow coronary flow (group II, 47 males, 24 females, mean age = 50 +/- 8 years). Coronary flow rates of all subjects were documented by thrombolysis in myocardial infarction frame count (TIMI frame count). QT interval duration and QT dispersion of all subjects were measured on the standard 12-lead electrocardiogram. RESULTS: There was no statistically significant difference between the two groups in respect to age, gender, presence of hypertension, and diabetes mellitus. There was a significant difference between the two groups in respect to the presence of cigarette smoking, typical angina, and positive exercise test results. TIMI frame counts of group I patients were significantly higher than those of group II patients for all three coronary arteries (P < 0.001). Maximum corrected QT interval (QTcmax) of group I did not differ from the QTcmax of group II (P > 0.05). However, minimum corrected QT interval (QTcmin) of group I was significantly lower than that for group II (P = 0.008). Consequently, corrected QT dispersion (QTcd) in group I was found to be significantly higher than in group II (P < 0.001). CONCLUSION: QTcd, indicating increased risk for ventricular arrhythmias and cardiovascular mortality, was found to be significantly higher in patients with slow coronary artery flow. However, further long-term prospective studies should be carried out to establish the significance of QTcd as a risk factor for ventricular arrhythmias and subsequent sudden cardiac death in patients with slow coronary artery flow.