Omer Alyan

Imaging of coronary artery anomalies: the role of multidetector computed tomography.

BackgroundCoronary artery anomalies are evaluated by using catheter-based angiography. Multidetector row-computed tomography (MDCT) is a new noninvasive imaging technique that has excellent spatial resolution for detecting the origin and course of a coronary anomalous vessel. ObjectiveTo determine the sensitivity of multidetector computed tomography in patients who had coronary artery anomaly demonstrated by conventional coronary angiography. Material and methodsA retrospective evaluation to identify 23 patients, who underwent retrospective electrocardiographic (ECG)-gated MDCT, was done and in whom an anomalous coronary vessel was found at a single center. Metoprolol (50–100 mg) was given orally to all patients to reduce heart rate so as to get high-quality MDCT images. After performing MDCT, the CT scans of each patient were analysed and compared with their coronary angiograms by two experienced radiologists and one cardiologist who were unaware about the study, and the sensitivity of MDCT was determined. ResultsTwenty-three patients (age range 28–73) with seven different coronary arteries of the anomalous type were evaluated. Nineteen patients had an anomalous left coronary artery; three patients had an anomalous single coronary artery; and one patient had an anomalous right coronary artery. The most common anomaly type was the left circumflex coronary artery (52%). The origin and course of all anomalous vessels were detected by ECG-gated MDCT (Lightspeed 16, GE Medical Systems, Milwaukee, Wisconsin, USA). The sensitivity of 100% of MDCT was detected in patients who had anomalous coronary vessels. ConclusionWe suggest that MDCT could be a non-invasive alternative imaging technique to conventional coronary angiography for screening the anomalous vessels of coronary arteries because of its excellent spatial resolution, which is very important for detecting the relationship of anomalous vessels with great arteries and cardiac structures.

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.

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.

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.

QT Dispersion Significantly Increases after Implantable Cardioverter-Defibrillator Shocks

Objective: To determine whether QT dispersion (QTd), a noninvasive electrocardiographic parameter of ventricular tachyarrhythmia risk assessment, is changed by implantable cardioverter‐defibrillator (ICD) shocks delivered during implantation process, to analyze the duration of these changes, and to further evaluate the effect of amiodarone on these parameters.

Do collaterals affect heart rate variability in patients with acute myocardial infarction

BackgroundThe protective effects and the prognostic importance of collaterals during and after acute myocardial infarction (MI) are under debate and heart rate variability (HRV) is a strong predictor of risk of mortality and arrhythmic events after acute MI. We aimed to examine the effects of collateral circulation on HRV in the early period after acute MI. MethodsSixty-four patients admitted to our clinics who were diagnosed with acute anterior MI and underwent thrombolytic therapy were enrolled in this study. We applied 24 h Holter monitoring for HRV analysis to all patients and compared the patients with and without collaterals to the infarct-related artery. ResultsMean heart rate, low frequency (LF) (day, night and 24 h) and LF/high frequency (HF) (day, night and 24 h) were higher, SD of all NN intervals (SDNN), root mean square of successive differences (RMSSD), number of NN intervals that differed by more than 50 ms from the adjacent interval divided by the total number of all NN intervals (PNN50) and HF night values were lower in patients without collaterals than in those with collaterals. SDNN was negatively correlated with left anterior descending coronary artery (LAD) stenosis, ventricle score indices and left ventricular ejection fraction (LVEF); LF/HF ratio was positively correlated with ventricle score indices and negatively correlated with LVEF and Thrombolysis in Myocardial Infarction flow grade. Linear regression analysis showed that ventricle score index and coronary collaterals affect HRV and LAD stenosis, ventricle score, LVEF and coronary collaterals affect LF/HF ratio. A SDNN <80 ms increased the development of ventricular arrhythmias in the early period by 4.7 fold, a LF/HF ratio >2.7 increased it by 9.8 fold and a LVEF <35% increased it by 12.8 fold, whereas the presence of well-developed collaterals decreased the arrhythmia development by 2.5 fold. ConclusionsThe collaterals to the infarct-related artery have great impact on HRV, autonomic nervous system activity and the development of ventricular arrhythmias in patients with acute anterior MI. Our results suggest a protective role of collaterals on myocardial electrophysiology in the early period after acute MI.

Systolic total narrowing of left anterior descending coronary artery and flow interruption secondary to myocardial bridge: a rare case report and review of literature.

A 33‐y‐old man was admitted to the emergency department with sudden onset of severe substernal chest pain radiating to the left arm and neck. No pathological signs were recorded upon physical examination. The admission electrocardiogram (ECG) recorded during chest pain showed a large anterior wall myocardial infarction. Intravenous (IV) infusion of 1.5 million units of streptokinase over 1 h was initiated. Coronary angiography revealed total narrowing and flow interruption in the midsegment of the left anterior descending (LAD) coronary artery secondary to a myocardial bridge during systole and disappearance with diastole. He was discharged on aspirin (300 mg/d), metoprolol (100 mg/d), enalapril (10 mg twice daily), and atorvastatin (40 mg/d) treatment at the follow‐up period. Copyright

A Case of Pulmonary Alveolar Microlithiasis with Cardiac Constriction Secondary to Severe Adjacent Pleural Involvement

Pulmonary alveolar microlithiasis (PAM) is a rare disorder of uncertain etiology and pathogenesis that is characterized by tiny calcium phosphate depositions in lung alveoli. Ectopic organ involvement has been reported infrequently. We hereby present a patient with PAM complicated by severe pleural calcification that has caused a constrictive cardiac physiology, a heretofore unknown occurrence/association. Based on our observations in this particular case, we suggest that a non-invasive echocardiographic examination may be well worth in the investigation of PAM patients in whom symptom onset at an early age has occurred, particularly if severe pleural calcification adjacent to the heart is present.

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.