The Effects of Spinal Anesthesia on QT Interval in Preeclamptic Patients

In this study, we measured the effects of spinal anesthesia on the corrected QT (QTc) interval in women with severe preeclampsia. Twenty-five preeclamptic (preeclamptic group) and 25 healthy pregnant women with normal arterial blood pressure and QTc interval (control group) were enrolled in this prospective, case-controlled study. Arterial blood pressure, heart rate, and QTc interval values were obtained before (baseline value) and at 5, 10, 20, 30, 60, and 120 min after initiation of spinal anesthesia. Total ephedrine dose, time elapsed until sensory block, and Apgar scores were recorded. Prior to spinal anesthesia, QTc interval values were significantly higher in the preeclamptic group (452 +/- 17.5 ms) when compared with that in controls (376 +/- 21.4 ms). Although the QTc interval shortened during spinal anesthesia when compared with baseline value in the preeclamptic group (P < 0.05), it showed no significant change in the control group. In conclusion, the QTc interval may be prolonged in severe preeclamptic patients who have hypertension and hypocalcemia. Spinal anesthesia for cesarean delivery may normalize that prolonged QTc interval due to sympathetic blockade.

Effects of sevoflurane on QT dispersion and heart rate variability

The purpose of this study was to use estimates of corrected QT dispersion (QTcd) and heart rate variability (HRV) to assess the effects of sevoflurane, an inhalation agent used frequently in clinical practice, on autonomic cardiac function. This study was conducted prospectively and in a blind manner on 20 women between 38 and 51 y of age who were classified as American Society of Anesthesiologists stage I-II and whose treatment required total abdominal hysterectomy. Electrocardiograms were recorded by 12-lead Holter monitor for 5 min before sevoflurane induction and again for 5 min at 10 min after tracheal intubation. Data on the first recording were considered as baseline; those on the second recording were viewed as final data. The study was terminated at this point, and surgery was allowed to proceed. QTcd and HRV values were assessed by a cardiologist, who was blinded to all data. All parameters were expressed as a mean value +/- standard deviation. Wilcoxon's test was used to compare baseline and final data. Statistical significance was considered as P<.05. No significant changes were observed between baseline and final QTcd values and between low- and high-frequency components (LF and HF) of HRV; nor were changes seen in the LF/HF ratio. With the patient under sevoflurane/ nitrous oxide anesthesia, no significant changes were detected in QTcd, LF, and HF values, and in the LF/HF ratio, whereas a significant increase (P=.001) was seen in standard deviation of the R-R interval, which was used as a measure of cardiac autonomic tone.

Effects of Intravenous Lidocaine on QTd and HRV Changes Due to Tracheal Intubation During Sevoflurane Induction

The aim of the present study was to evaluate the effects of IV lidocaine on autonomic cardiac function changes in tracheal intubation (TI) during sevoflurane anaesthesia by using more reliable parameters, namely, the analysis of QT dispersion and heart rate variability (HRV) from Holter monitoring. In this prospective, double-blind study, 44 American Society of Anaesthesiologists class I-II patients scheduled for hysterectomy were randomly and equally divided into 2 groups; a control sevoflurane group (group S, n = 22) and a lidocaine sevoflurane group (group LS, n = 22). Before the induction of anaesthesia, the electrocardiograms (ECG) of all patients were recorded for 3 minutes as baseline parameters. In both groups, the anaesthesia was induced with 7% sevoflurane in O(2 )at 6L min(-1) via a facemask for 2 minutes. However, before the induction of sevoflurane anaesthesia in group LS, 1 mg kg(-1) of lidocaine was given intravenously (IV). For muscle relaxation during TI, vecuronium was given to all participants. Three minutes after administration of vecuronium, TI was performed and an ECG was recorded synchronously for another 3 minutes. The results from the later records were used as postintubation parameters. Baseline and postintubation data were analysed. When compared to baseline values, postintubation LF/HF and SDNN values were increased in group S (P = 0.005, P = 0.001, respectively), whereas postintubation LF and HF values were decreased in group LS (P = 0.014, P = 0.041, respectively). Under the influence of sevoflurane anaesthesia, TI resulted in sympathetic activation. However, this activation was attenuated by the administration of IV 1 mg kg(-1) lidocaine 5 minutes prior to TI.

Functional and morphological cardiac changes in myeloproliferative disorders (clinical study)

PURPOSE

Cardiac involvement is not well defined in myeloproliferative disorders (MPD). The purpose of this study was to evaluate the cardiac involvement by transthoracic echocardiography in MPD.

MATERIALS AND METHODS

The study groups were 36 patients (mean age: 58+/-15 years, 20 female and 16 male) with MPD and 30 age-matched healthy controls. MPD group included 15 essential thrombocythemia (ET), eight chronic phase chronic myelogenous leukemia (CML), seven idiopathic myelofibrosis (MF) and six polcythemia vera patients.

RESULTS

Valvular regurgitations were present in 14 patients (39%) and eight controls (27%), (P>0.05). Mitral regurgitation (MR) was more prominent in CML compared to controls (P=0.044). The rates of annular calcifications, valvular thickening, and vegetation like lesions were not different between MPD and control groups. Pulmonary hypertension (PHT) was present in six (17%) patients, but none of the controls (P=0.021). The rates of PHT in CML and MF were significantly higher than controls (P<0.05). The rate of PHT was not different in-between MPD patients with and without thromboembolic events, however, in MPD cases with thromboembolic events PHT was more common compared to controls (P=0.037).

CONCLUSION

This study showed that valvular lesions were not more prevalent in MPD. PHT was the most prominent cardiac pathology in MPD (especially in CML, MF and thromboembolic events subgroups) compared to controls. Further evaluation of the cardiac changes in MPD subgroups with extended studies including trans-oesophageal echocardiography and longer follow-up periods would be appropriate.

A New Perspective on Cardiotoxicity of 5-Fluorouracil

BACKGROUND

The pathophysiology of 5-fluorouracil (5-FU) cardiotoxicity is still controversial. The objective of this study was to assess the influence of high-dose leucovorin and infusional 5-FU regimen (HDLV5FU) on cardiac tissues.

METHODS

We monitored 28 patients (median age 68 years) under HDLV5FU chemotherapy with complete blood counts, cardiac enzymes, C-reactive protein, coagulation tests, Holter electrocardiogram, and conventional echocardiography. Cardiac ultrasonic tissue characterization with integrated backscatter (IBS) analysis was performed in the 16 last enrolled patients.

RESULTS

The magnitude of both anterior and posterior cardiac IBS values significantly decreased at the 48th hour of treatment compared to both 0th hour and day 15 (p < 0.003). Cardiac IBS values on the 15th day were not different from the 0th hour. Clinical cardiotoxicity was not observed and other monitored parameters did not change significantly in any patient (p > 0.5 for all).

CONCLUSION

Cardiac IBS analysis suggests that 5-FU might cause reversible subclinical myocardial dysfunction.

Cardiac cyclic variation of integrated backscatter in hypertension and dialysis patients

BACKGROUND

Cyclic variation of myocardial-integrated backscatter (CV-IB) offers a non-invasive myocardial contractile performance assessment. There is limited data concerning CV-IB in end-stage renal disease (ESRD) patients.

METHODS

Forty essential hypertensive (EH) patients (mean age 51+/-8 yrs) and 24 ESRD patients (mean age 49+/-14 yrs) were compared to 10 healthy controls (mean age 45+/-10 yrs). A 2D-Doppler echocardiography with digitized imaging was performed to characterize myocardial ultrasonic tissue by CV-IB between systole and diastole at the interventricular septum (IVS) and left ventricular (LV) posterior wall (PW).

RESULTS

There was no significant difference between age and sex among groups. Systolic and diastolic blood pressures (BP) were both higher in EH patients (157/96 mmHg in EH, 129/81 mmHg in ESRD and 115/77 mmHg in controls, p<0.001). Left ventricular mass index (LVMI) was higher in EH and ESRD patients than in controls (respectively, 119+/-37, 130+/-46, 87+/-12 g/m2, p<0.05), while there was no significant difference found between EH and ESRD patients. EH patient CV-IB values were significantly lower than in ESRD patients and controls (respectively, 6.9+/-1.6, 8.6+/-0.7, 10.6+/-1.1 dB, p<0.001 for IVS, 7.7+/-1.3, 8.7+/-0.8, 10.4+/-1.1 dB, p<0.001 for PW). CV-IB for PW and IVS were significantly lower in ESRD patients than in controls (p<0.001).

CONCLUSIONS

CV-IB can offer useful parameters for myocardial structure in EH and ESRD patients. Further studies are needed to clarify CV-IB in ESRD patients.

Asymptomatic pericardial effusion in chronic myelogenous leukemia

In chronic myelogenous leukemia (CML), pericardial effusions are rarely seen. Pericardial tamponade may occur in many of the patients with pericardial effusion. Here in a 45-year-old male with newly diagnosed chronic phase of Philadelphia chromosome (the Ph)-positive CML, asymptomatic pericardial effusion was detected by echocardiography. The pericardial effusion disappeared after chemotherapy without pericardiocentesis, within six months. Pericardial effusion should always be suspected in patients with chronic phase of CML, even though they are asymptomatic. In our case the pericardial effusion was probably due to extramedullary haematopoiesis because it improved with chemotherapy. Follow-up with echocardiography was sufficient in this case.