Assessment of electrocardiographic parameters in adult patients undergoing extracorporeal shockwave lithotripsy.

OBJECTIVE: Extracorporeal shock wave lithotripsy (ESWL) is a safe and effective treatment for urinary tract calculi. While serious side effects are rare, transient cardiac arrhythmias may occur. New electrocardiographic (ECG) parameters, such as P wave dispersion (PWD), QT dispersion (QTd), T peak to T end (Tp-e) interval, Tp-e interval/QT ratio, and Tp-e interval/corrected QT ratio have been defined to help predict atrial and ventricular arrhythmias. However, effect of ESWL on these ECG parameters has not been previously investigated. The present study was an examination of the effect of ESWL on ECG parameters. METHODS: Total of 40 consecutive patients who underwent ESWL were prospectively enrolled in the study. Pre-procedure ECG parameters were compared with post-procedure ECG parameters. RESULTS: PWD values were significantly longer on post-procedure ECG compared with pre-procedure ECG (p=0.017). Corrected QT duration and QTd were significantly longer on postprocedure ECG compared with pre-procedure ECG (p=0.046 and p=0.008, respectively). In addition, Tp-e interval, Tp-e interval/QT ratio, and Tp-e interval/QTc ratio were significantly longer post procedure (p=0.035, p=0.045, and p=0.022, respectively). In univariate correlation analysis, duration of procedure was significantly correlated with post-procedure PWD, QTc, and QTD values. CONCLUSION: Clinical use of ECG parameters may be helpful in monitoring of patients receiving ungated ESWL in order to detect cardiac dysrhythmia.

The risk of false results in the assessment of platelet function in the absence of antiplatelet medication: comparison of the PFA-100, multiplate electrical impedance aggregometry and verify now assays.

OBJECTIVES: Evaluation of aspirin (ASA) responsiveness with platelet function tests varies by the choice of blood mixture and functional test and cut off values for defining the the treatment used. Addition to that we also aimed to determine agreement between three tests and to research whether there is any necessity to measure baseline platelet activity. METHODS: The study group comprised of 52 patients with multiple risk factors receiving primary prophylaxis of ASA (100 mg/day). For each patient inhibition of platelet aggregation with aspirin was determined using three different whole blood tests: Multiplate electrical impedance aggregometry, Verify Now Aspirin, and collagen-epinephrine closure time PFA-100. Platelet aggregation was assessed with multiplate electrical impedance aggregometry,and was defined as the area under curve (AUC,AUxmin). Maximal 6,4 microM collagen-induced AUC were used to quantify platelet aggregation due to ASA. The ASA response was defined as >30 % reduction in basal platelet aggregation with multiplate electrical impedance aggregometry. Collagen induced platelet aggregation at the Verify Now Aspirin assay quantitated the ASA-induced platelet inhibition as aspirin reaction units (ARU). According to manufacturer insert ARU>550 indicates aspirin resistance. ASA platelet function studies were assessed twice at baseline (pre-aspirin), and after 7 day(post-aspirin) were performed. RESULTS: After ASA intake none of the patients was found aspirin resistant with PFA-100. (CEPI-CT (129+/-36 vs 289+/-18 ). None of the patients was found aspirin resistant with PFA-100. As>30 % reduction in basal platelet aggregation with multiplate electrical impedance aggregometry is selected all of the patients have been stratified as responders.(COL TEST 688+/-230 vs 169+/-131 AU) None of the patients with Verify Now Aspirin found resistance to ASA(594+/-62 vs 446+/-43).Prior to ASA intake 15 of all patients with VN(501+/-16) and 2 of all patients with multiplate electrical impedance aggregometry (223+/-40 AUC )aggregation levels below the cut off label before ingestion of ASA.None of the patients was above the cut off label with PFA -100 (129+/-36). CONCLUSIONS: Verify Now ASA assay, multiplate electrical impedance aggregometry and PFA-100 seem to be reliable tests in reflecting ASA effect on platelets. Cut off labels for the defining the responsiveness given by manufacturer may show significant interindividual variability with Verify Now ASA assay and multiplate electrical impedance aggregometry, and these test may show platelet inhibition despite the absence of ASA intake. Consideration of the pretreatment values may eliminate the risk of overestimation in the assessment of platelet inhibition by ASA.