Early Risk stratification for Arrhythmic death in Patients with ST-Elevation Myocardial Infarction

BACKGROUND: Sudden cardiac death is a leading cause of death in patients with ST-elevation myocardial infarction (MI). According to high cost of modern therapeutic modalities it is of paramount importance to define protocols for risk stratification of post-MI patients before considering expensive devices such as implantable cardioverter-defibrillator. METHODS: One hundred and thirty seven patients with acute ST-elevation MI were selected and underwent echocardiographic study, holter monitoring and signal-averaged electrocardiography (SAECG). Then, the patients were followed for 12 ±3 months. RESULTS: During follow-up, 13 deaths (9.5%) occurred; nine cases happened as sudden cardiac death (6.6%). The effect of ejection fraction (EF) less than 40% on occurrence of arrhythmic events was significant (P<0.001). Sensitivity and positive predictive value of EF<40% was 100% and 76.95% respectively. Although with lesser sensitivity and predictive power than EF<40%, abnormal heart rate variability (HRV) and SAECG had also significant effects on occurrence of sudden death (P=0.02 and P=0.003 respectively). Nonsustained ventricular tachycardia was not significantly related to risk of sudden death in this study (P=0.20). CONCLUSION: This study indicated that EF less than 40% is the most powerful predictor of sudden cardiac death in post MI patients. Abnormal HRV and SAECG are also important predictors and can be added to EF for better risk stratification

Early septal activation, successful lateral ablation

The coronary sinus activation pattern is an important clue for the detection of arrhythmia mechanisms and/or localization of accessory pathways. Any change in this pattern during radiofrequency ablation should be evaluated carefully to recognize the presence of another accessory pathway or innocence of the accessory pathway during arrhythmia. Intra-atrial conduction block can change the coronary sinus activation pattern. Negligence regarding this phenomenon can cause irreversible complications. Here we describe a case with left lateral accessory pathway conduction in which intra-atrial conduction block completely reversed the coronary sinus activation pattern. (Cardiol J 2008; 15: 181-185

The effect of preoperative aspirin use on postoperative bleeding and perioperative myocardial infarction in patients undergoing coronary artery bypass surgery

Background: We tried to evaluate the clinical outcomes (mortality, postoperative bleeding and perioperative myocardial infarction) of patients who underwent first elective coronary artery bypass grafting and received aspirin during the preoperative period. Methods: The study was a prospective, randomized and single-blinded clinical trial. Two hundred patients were included and divided into two groups. One group received aspirin 80-160 mg, while in the other aspirin was stopped at least seven days before surgery. The primary end-points of the study were in-hospital mortality and hemorrhage-related complications (postoperative blood loss in the intensive care unit, re-exploration for bleeding and red blood cell and non-red blood cell requirements). The secondary end-point was perioperative myocardial infarction. Results: There were no differences in patient characteristics between the aspirin users and non-aspirin users. We found a significant difference between postoperative blood loss (608 &#177; 359.7 ml vs. 483 &#177; 251.5 ml; p = 0.005) and red blood cell product requirements (1.32 &#177; 0.97 unit packed cell vs. 0.94 &#177; 1.02 unit packed cell; p = 0.008). There was no significant difference between the two groups regarding platelet requirement and the rate of in-hospital mortality and re-exploration for bleeding. Similarly, we found no significant difference in the incidence of definite and probable perioperative myocardial infarction (p = 0.24 and p = 0.56 respectively) or in-hospital mortality between the two groups. Conclusion: Preoperative aspirin administration increased postoperative bleeding and red blood cell requirements with no effect on mortality, re-exploration rate and perioperative myocardial infarction. We recommend withdrawal of aspirin seven days prior to surgery. (Cardiol J 2007; 14: 453-457

A patient with sick sinus syndrome, atrial flutter and bidirectional ventricular tachycardia: Coincident or concomitant presentations?

Channelopathies are among the major causes of syncope or sudden cardiac death in patients with structurally normal hearts. In these patients, the atrium, ventricle or both could be affected and reveal different presentations. In this case, we present a patient with an apparently structurally normal heart and recurrent syncope, presented as sick sinus syndrome with atrial flutter and bidirectional ventricular tachycardia. (Cardiol J 2007; 14: 585-588)

Relationship between QRS complex notch and ventricular dyssynchrony in patients with heart failure and prolonged QRS duration

Background: Cardiac resynchronization therapy (CRT) has been accepted as an established therapy for advanced systolic heart failure. Electrical and mechanical dyssynchrony are usually evaluated to increase the percentage of CRT responders. We postulated that QRS notch can increase mechanical LV dyssynchrony independently of other known predictors such as left ventricular ejection fraction and QRS duration. Methods: A total of 87 consecutive patients with advanced systolic heart failure and QRS duration more than 120 ms with an LBBB-like pattern in V1 were prospectively evaluated. Twelve-lead electrocardiogram was used for detection of QRS notch. Complete echocardiographic examination including tissue Doppler imaging, pulse wave Doppler and M-mode echocardiography were done for all patients. Results: Eighty-seven patients, 65 male (75%) and 22 female (25%), with mean (SD) age of 56.7 (12.3) years were enrolled the study. Ischemic cardiomyopathy was the underlying heart disease in 58% of the subjects, and in the others it was idiopathic. Patients had a mean (SD) QRS duration of 155.13 (23.34) ms. QRS notch was seen in 49.4% of the patients in any of two precordial or limb leads. Interventricular mechanical delay was the only mechanical dyssynchrony index that was significantly longer in the group of patients with QRS notch. Multivariate analysis revealed that the observed association was actually caused by the effect of QRS duration, rather than the presence of notch per se. Conclusions: QRS notch was not an independent predictor of higher mechanical dyssynchrony indices in patients with wide QRS complex and symptomatic systolic heart failure; however, there was a borderline association between QRS notch and interventricular delay

Predictors of ventricular tachycardia induction in syncopal patients with mild to moderate left ventricular dysfunction

Background: In patients with mild to moderate left ventricular dysfunction (LVD) (35% &#163; LVEF &#163; 50%) who present with syncope, demonstration of tachy and/or brady-arrhythmia has prognostic value. In this group of patients electrophysiological study (EPS) is often necessary. Methods: A total of 53 consecutive patients with mild to moderate LVD and history of undetermined syncope underwent EPS. Sinus node function, His-Purkinje system conduction and ventricular electrical stability were evaluated. Results: Twenty eight patients (52.8%) had induction of sustained monomorphic ventricular tachycardia (VT) and five (9.4%) patients had a sustained ventricular arrhythmia other than monomorphic VT (ventricular flutter, ventricular fibrillation, and polymorphic VT) induced during EPS. Abnormal sinus node function and/or His-Purkinje system conduction was found in five (9.4%) patients. Age, gender, history of myocardial infarction, type of underlying heart disease and history of revascularization were not predictors of VT induction. Wide QRS morphology independently, and lower left ventricular ejection fraction and presence of pathologic q wave in precordial leads dependently, could increase risk of VT induction. Conclusions: The EPS can determine which patient with syncope and mild to moderate LVD is likely to benefit from placing an ICD for prevention of sudden cardiac death. Pathologic precordial q wave, wide QRS morphology and lower left ventricular ejection fraction could be predictors of VT induction during EPS. Wide QRS morphology has an independent effect in this category

Wpływ przedoperacyjnego stosowania kwasu acetylosalicylowego na występowanie krwawienia pooperacyjnego i okołooperacyjnego zawału serca u osób poddawanych pomostowaniu aortalno-wieńcowemu

Wstęp: Podjęto próbę oceny wyników klinicznych (śmiertelność, występowanie krwawienia pooperacyjnego i okołooperacyjnego zawału serca) u pacjentów, których poddano pierwszej operacji pomostowania aortalno-wieńcowego, otrzymujących w okresie przedoperacyjnym kwas acetylosalicylowy. Metoda: Do prospektywnego, randomizowanego badania przeprowadzonego metodą ślepej próby włączono 200 pacjentów, których podzielono na dwie grupy. Osoby z jednej z nich otrzymywały kwas acetylosalicylowy w dawce 80&#8211;160 mg, natomiast chorzy z drugiej grupy przyjmowanie tego leku zakończyli przynajmniej 7 dni przed operacją. Pierwotnymi punktami końcowymi badania były: zgon w trakcie hospitalizacji i powikłania związane z krwawieniem (pooperacyjna utrata krwi na oddziale intensywnej opieki medycznej, reoperacja z powodu krwawienia oraz konieczność przetoczeń koncentratu krwinek czerwonych lub innych preparatów krwiopochodnych). Za wtórny punkt końcowy przyjęto występowanie okołooperacyjnego zawału serca. Wyniki: Pacjenci leczeni kwasem acetylosalicylowym nie różnili się w zakresie charakterystyki od osób, u których nie wdrożono tej formy terapii. Stwierdzono natomiast istotną różnicę w wielkości pooperacyjnej utraty krwi (608 &#177; 359,7 ml vs. 483 &#177; 251,5 ml; p = 0,005) i konieczności przetoczeń masy erytrocytarnej (1,32 &#177; 0,97 j. vs. 0,94 &#177; 1,02 j.; p = 0,008). Grupy nie różniły się w zakresie zapotrzebowania na płytki krwi i liczby zgonów szpitalnych oraz częstości reoperacji z powodu krwawienia. Nie wykazano również istotnych statystycznie różnic między grupami w występowaniu rzeczywistego i prawdopodobnego zawału serca (odpowiednio p = 0,24 i p = 0,56) oraz śmiertelności wewnątrzszpitalnej. Wnioski: Stosowanie kwasu acetylosalicylowego przed operacją zwiększało krwawienie pooperacyjne i konieczność przetoczeń masy erytrocytarnej, nie wpływając na liczbę zgonów, częstość reoperacji i występowanie okołooperacyjnego zawału serca. Zaleca się odstawienie kwasu acetylosalicylowego na 7 dni przed operacją (Folia Cardiologica Excerpta 2008; 3: 35&#8211;39

Can prodromal symptoms predict recurrence of vasovagal syncope?

Background: Vasovagal syncope (VVS) is a common symptom with empirical therapy and high recurrence rate. Our goal was to determine whether the pattern of presyncopal prodromal symptoms can predict the recurrence probability of vasovagal syncope. Methods: Seventy-nine consecutive patients (male/female: 53/26) with history of VVS and positive tilt table test (TTT) were enrolled in the study and completed the follow-up time for one year. They all had normal electrocardiograms and cardiac echocardiography without underlying disease. All of them were evaluated meticulously for prodromal symptoms (diaphoresis, nausea, palpitation and blurred vision) and frequency of syncopal spells in their past medical history. They received metoprolol at maximum tolerated dose and were taught tilt training as an empirical therapy after TTT. Results: Fifty-four patients (68.4%) reported at least one of the four main prodromal symptoms. Median syncopal &#177; presyncopal spells were 4 episodes. Forty-two patients (53.2%) experienced recurrence of syncope or presyncope during the follow-up period. In recurrent symptomatic patients, diaphoresis had been more significantly reported in their past medical history (p = 0.018) and they had more syncopal spells before TTT (p = 0.001). Age, gender and type of TTT response did not have any effect on the recurrence of VVS. Conclusions: Patients with a history of diaphoresis as a prodromal symptom and more pretilt syncopal attacks experience more syncopal or presyncopal spells during follow-up

Complex genetic background in a large family with Brugada syndrome.

The Brugada syndrome (BrS) is an inherited arrhythmia characterized by ST-segment elevation in V1-V3 leads and negative T wave on standard ECG. BrS patients are at risk of sudden cardiac death (SCD) due to ventricular tachyarrhythmia. At least 17 genes have been proposed to be linked to BrS, although recent findings suggested a polygenic background. Mutations in SCN5A, the gene coding for the cardiac sodium channel Nav1.5, have been found in 15-30% of index cases. Here, we present the results of clinical, genetic, and expression studies of a large Iranian family with BrS carrying a novel genetic variant (p.P1506S) in SCN5A. By performing whole-cell patch-clamp experiments using HEK293 cells expressing wild-type (WT) or p.P1506S Nav1.5 channels, hyperpolarizing shift of the availability curve, depolarizing shift of the activation curve, and hastening of the fast inactivation process were observed. These mutant-induced alterations lead to a loss of function of Nav1.5 and thus suggest that the p.P1506S variant is pathogenic. In addition, cascade familial screening found a family member with BrS who did not carry the p.P1506S mutation. Additional next generation sequencing analyses revealed the p.R25W mutation in KCNH2 gene in SCN5A-negative BrS patients. These findings illustrate the complex genetic background of BrS found in this family and the possible pathogenic role of a new SCN5A genetic variant