Žarko Mavrić

Relationship between QT dispersion and the incidence of early ventricular arrhythmias in patients with acute myocardial infarction

There is controversy about the influence of QT dispersion on the incidence of early ventricular arrhythmias in patients with acute myocardial infarction (AMI). The QT and QTc dispersion (QTd, QTcd) between two groups of patients with AMI were compared: 39 patients with early sustained ventricular tachycardia or ventricular fibrillation (VT/VF) and 40 patients without such arrhythmias. QTd and QTcd were calculated from the admission and predischarge ECG, expressed as the difference between the maximum and minimum QT and QTc interval in 12 leads. The coefficient of variability was also calculated (VQT, VQTc). Groups did not differ significantly in age, incidence of previous infarction, Killip class, electrolyte status, infarct location, expected and final ECG infarct size, enzymatic infarct size, thrombolytic treatment and reperfusion rate, i.e., in variables that could influence the VT/VF occurrence. On admission, patients with VT/VF had significantly greater QTd (77+/-23 vs 53+/-27 ms, P<0.001) and QTcd (90+/-29 vs 62+/-28 ms, P<0.001); VQT and VQTc were also significantly higher. Although similar differences existed on predischarge ECG, they were smaller. The results indicate that QT dispersion varies during the illness, and that measurements of QT dispersion could be helpful in predicting serious ventricular arrhythmias.

Assessment of Hemodialysis Adequacy by Ionic Dialysance: Comparison to Standard Method of Urea Removal

Background. The hemodialysis adequacy is one of the most important issues influencing the survival of patients on maintenance hemodialysis (HD). Assessment of measuring the delivered dialysis dose using clearance × time/volume (Kt/V) index requires multiple blood sampling. New methods for assessment of dialysis dose based on ionic dialysance (ID) have been suggested. Online conductivity monitoring (using sodium flux as a surrogate for urea) allows the repeated noninvasive measurement of Kt/V on each HD treatment. In this study we have compared this method with the standard method of estimating Kt/V. Methods. We studied 24 established HD patients over a 4 week time period. Patients were dialyzed using Fresenius 4008S dialysis monitors, equipped with modules to measure ID. Data were manually collected and analyzed using the appropriate statistical software. Urea removal (UR) was measured once a week by a two-pool calculation, estimating an eKt/V. Results. The Kt/V measured by ID highly correlated with the one derived from the measurement of the UR (r = 0.8959, p< 0.0001). The ID underestimated UR by the mean of 6%. The ID varied greatly within individual patients with a median of 1.29 ± 0.22. If the eKt/V ≥ 1.2 is considered adequate, 33% of the patients would have been inadequately dialyzed. The mean HD duration to achieve an adequate dialysis was 4 hours and 47 minutes with high interpatient variability. Conclusion. The ID seems to be an easily obtained measure of the delivered dialysis dose, correlating well with standard UR method. Substantial individual variations imply that repeated measures (ideally for all treatments) are necessary to obtain a real answer to the mean treatment dose being delivered to the patients.

Acute renal failure due to pericardial tamponade in a 60-year-old male patient

Abstract Acute renal failure (ARF) is still a considerable factor in hospital morbidity and mortality. This clinical condition occurs in up to 25% of critically ill patients. Mortality in these patients varies widely depending on the cause. ARF in the context of a large pericardial effusion and pericardial tamponade has not often been reported. This paper presents a case of life-threatening pericardial tamponade and a consecutive rapid onset of ARF. Successful treatment with pericardiocentesis was performed, which was followed by restitution of renal function.

Influence of the type and degree of left ventricular hypertrophy on the prevalence of ventricular arrhythmias in patients with hypertensive heart disease.

Purpose:To investigate the correlation between the prevalence of ventricular arrhythmias (VA) and the type and degree of left ventricular hypertrophy (LVH) in hypertensive patients using exercise testing and Holter monitoring.Patients and Methods:A total of 192 patients (87 men and 105 women) without coronary disease were divided into three groups according to type of LVH (concentric, eccentric, and asymmetric) and three subgroups in relation to the degree of hypertrophy (mild, moderate, and severe). In all subjects blood pressure was measured, electrocardiographic and echocardiographic data obtained and the prevalence of VA determined by Holter monitoring and bicycle ergometry.Results:The most frequent LVH type was the concentric (63%), followed by eccentric (28%) and asymmetric (9%). Severe LVH was found in 10% of patients. Complex VA during Holter monitoring were identified in > 40% of patients. During the stress test this percentage increased by additional 7.4%. There was no statistically significant difference between groups in frequency of simple (p = 0.757) and complex (p = 0.657, p = 0.819, p = 0.617, for polytopic, pairs and ventricular tachycardia, respectively) VA. Increased prevalence of VA was found for the moderate and severe degree in all types. In the concentric type the difference was statistically significant for simple VA (p = 0.042).Conclusion:There was no correlation between type of LVH and prevalence of VA. The severity of hypertrophy contributes more to a greater prevalence of VA than the LVH pattern. The combination of severe degree and concentric type carries the greatest cardiovascular risk.ZusammenfassungZiel:Die Wechselbeziehung zwischen der Prävalenz von ventrikulären Arrhythmien (VA), dem Typ und dem Grad der linksventrikulären Hypertrophie (LVH) bei Patienten mit Bluthochdruck sollte mittels Ergometrie und Langzeit-EKG untersucht werden.Patienten und Methodik:Insgesamt 192 Patienten (87 Männer und 105 Frauen) ohne Herzerkrankung wurden in drei Gruppen in Bezug auf den LVH-Typ (konzentrisch, exzentrisch und asymmetrisch) und in drei weitere Untergruppen gemäß dem Grad der Hypertrophie (leicht, mäßig und schwer) eingeteilt. Bei allen Patienten wurde der Blutdruck gemessen, elektrokardiographische und echokardiographische Daten wurden ermittelt, und die Prävalenz von VA wurde mittels Langzeit-EKG und Ergometrie festgestellt.Ergebnisse:Der am weitesten verbreitete LVH-Typ war der konzentrische (63%), gefolgt vom exzentrischen (28%) und asymmetrischen (9%). Eine schwere LVH wurde bei 10% der Patienten gefunden. Komplexe VA wurden mittels Langzeit-EKG bei > 40% der Patienten identifiziert. Mittels Ergometrie wurde dieser Prozentsatz um weitere 7,4% erhöht. Es gab keinen statistisch signifikanten Unterschied zwischen den Gruppen in Bezug auf einfache (p = 0,757) und komplexe VA (p = 0,657, p = 0,819, p = 0,617, für polytope, für Paare oder für ventrikuläre Tachykardie). Eine erhöhte Prävalenz von VA wurde für den mäßigen und schweren Grad bei allen Typen gefunden. Beim konzentrischen Typ war der Unterschied für die einfache VA statistisch signifikant (p = 0,042).Schlussfolgerung:Es gab keine Wechselbeziehung zwischen dem LVH-Typ und der Prävalenz von VA. Die Schwere der Hypertrophie ist bedeutender für die Prävalenz von VA als das LVH-Muster. Die Kombination aus schwerem Grad und konzentrischem Typ bringt das größte Risiko für Herz und Kreislauf mit sich.