Prognostic evaluation of QT-dispersion in elderly hypertensive and normotensive patients

Effects of esmolol on QTc interval changes during tracheal intubation: a systematic review

INTRODUCTION AND AIMS

Esmolol is an ultra-short-acting β₁ antagonist that has been shown to attenuate the corrected QT (QTc) interval prolongation associated with laryngoscopy and endotracheal intubation (LTI). Prolongation of the QTc interval can precipitate arrhythmias, the most serious of which is torsades de pointes . The aim of this systematic review was to compare esmolol and placebo on QTc changes occurring during LTI.

MATERIALS AND METHODS

PubMed, EMBASE, Cochrane Registry of Clinical Trials and CINAHL databases (up to August 2018) were screened for randomised controlled trials comparing esmolol and placebo on QTc changes during LTI in cardiac and non-cardiac surgeries. The primary outcome was QTc changes during LTI and secondary outcome was related to adverse effects from esmolol such as bradycardia and hypotension.

RESULTS

Seven trials were identified involving 320 patients, 160 patients receiving esmolol or placebo apiece. A shortening of the QTc post-LTI was evident in the esmolol group compared with the placebo in four studies. Compared with the baseline, the QTc was reduced post-LTI in the esmolol group. In the placebo group, the QTc was prolonged compared with the baseline post LTI. Nonetheless, esmolol did not prevent QTc prolongation in the remaining three studies, and much of this was attributed to employing QTc prolonging agents for premedication and anaesthetic induction. No significant adverse events were noted.

CONCLUSION

Compared with placebo, esmolol reduced the LTI-induced QTc prolongation when current non-QTc prolonging agents were chosen for tracheal intubation. Future studies should explore whether transmural dispersion (a marker of torsadogenicity) is also affected during LTI by analysing parameters such as the Tp-e interval (interval between the peak to the end of the T-wave) and Tp-e/QTc (rate corrected Tp-e interval).

TRIAL REGISTRATION NUMBER

CRD42018090282.

P-wave and QT dispersion in hypertensive disorders of pregnancy

Aim: To compare P-wave and QT dispersion values in hypertensive disorders of pregnancy and controls and also in preeclampsia, chronic hypertension, and gestational hypertension separately.Material and methods: We included 140 hypertensive pregnants and 110 healthy age-matched pregnants in this study. The hypertensive pregnants were divided into three subgroups: preeclampsia (n = 43), chronic hypertension (n = 51), and gestational hypertension (n = 46). P-wave and QT dispersion values were compared between groups.Results: Hypertensive pregnants had higher P-wave (41.74 ± 5.51 vs. 37.73 ± 5.62, p < .001) and QTc dispersion (45.44 ± 7.62 vs. 39.77 ± 8.34, p < .001) values. In subgroup analysis, P-wave dispersion and QTc dispersion were different between preeclamptic, chronic hypertensive, and gestational hypertensive patients. Also, they were significantly higher in chronic hypertension as compared to gestational hypertension and they were higher in preeclampsia than in gestational hypertension. No difference was found according to these parameters between preeclampsia and chronic hypertension. In correlation analysis, both P-wave dispersion and QTc dispersion were positively correlated with systolic (r = 0.409, p < .001 and r = 0.306, p < .001) and diastolic blood pressure (r = 0.390, p < .001 and r = 0.287, p < .001) which are main clinical determinants of hypertensive disorders.Conclusion: In clinical practice, chronic hypertensive pregnants are generally followed up in their future life for cardiovascular disorders. Also, we recommend that we must inform and follow preeclamptic patients for future cardiovascular diseases.

QTc dispersion and Cornell duration product can predict 10-year outcomes in hypertensive patients with left ventricular hypertrophy

BACKGROUND

Persistent and adequate treatment of patients with arterial hypertension leads to more favorable disease outcome.

HYPOTHESIS

Aside for the present left ventricular hypertrophy (LVH), there are other non-invasive parameters which can represent additional predictors of unfavorable prognosis in patients with essential arterial hypertension during the 10-year follow-up.

METHODS

A hypertensive group with LVH (124 patients; age 57.0 ± 8.0; 84 males and 40 females) was included in the study and examined noninvasively. Patients used regular medication therapy during the follow-up period.

RESULTS

During the 10-year follow-up period, unfavorable outcome was recorded for 40 (32.3%) patients. Patients with unfavorable outcome had higher baseline values of left ventricular mass index (178.9 ± 29.5 g/m² vs 165.5 ± 29.5 g/m² ; P < 0.05) and QTc dispersion (64.1 ± 24.7 ms vs 54.8 ± 19.4 ms; P < 0.05). Frequency of positive Cornell product was higher in the group of patients with unfavorable outcome (35% vs 22.2%; P < 0.01). Positive Lyon-Sokolow score did not show statistical significance (25% vs 11.9%; P = 0.06). Cornell product (β = 0.234; P < 0.01) and QTc dispersion >65 ms (β = 0.184; P < 0.05) had prognostic significance in LVH (multiple regression analysis: R = 0.314, R = 0.099, adjusted R = 0.084, standard error of the estimate = 0.449, P < 0.05).

CONCLUSIONS

Patients with a positive Cornell product and larger QTc dispersion had more unfavorable 10-year outcomes compared with other patients with LVH.

Subclinical ventricular repolarization abnormality in uncontrolled compared with controlled treated hypertension

Background

Antihypertensive medications have variable effects on the duration of the QT interval. This study aims to demonstrate the subclinical ventricular conduction defect in treating hypertensive patients taking in consideration the status of the blood pressure control with the antihypertensive agents.

Methods

This cross-section study was performed at the Departments of Physiology and Pharmacology, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq. A total number of 97 hypertensive patients (30 males and 67 females) were eligible to enroll in the study. The patients were grouped into controlled hypertension (Group I) and uncontrolled hypertension (Group II). Each participant is subjected to the electrocardiograph (ECG) investigation. A QT nomogram plot used to identify the patients who are vulnerable or at risk of developing cardiac arrhythmias.

Results

There were no significant differences in the values of the electrocardiogram determinants between Group I and Group II. Abnormal prolonged QTcB interval observed in 18 out of 80 (22.5%) patients of Group II compared with 4 out of 17. The JT index value of ≥112 was observed in 20 out of 80 (25%) patients of Group II compared with 6 out of 17 (35.3%) patients of Group I. A significant correlation between the QTcB duration with JT index observed in both Groups I and II.

Conclusion

Patients with hypertension have variability in ventricular repolarization (QTcB and JT) irrespective of their blood pressure control putting them at higher risk of cardiac arrhythmias.

Effect-site concentration of remifentanil for attenuating QTc interval prolongation following intubation in hypertensive female patients

BACKGROUND

Haemodynamic changes after sympathetic stimuli like tracheal intubation are more pronounced in hypertensive patients than in normotensive patients. Heart rate (HR)-corrected QT (QTc) interval changes related to intubation may also be more prominent in hypertensive patients. We hypothesised that there would be a difference in the effect-site concentration (Ce) of remifentanil to attenuate QTc interval prolongation in normotensive and hypertensive patients following intubation.

METHODS

Twenty-two normotensive and 22 hypertensive female patients (≥ 50 year) were enrolled and anaesthesised with remifentanil and propofol using a target-controlled infusion. All hypertensive patients received oral antihypertensive medications for > 6 months and took the medications in the morning of the surgery. The effective concentration of remifentanil Ce in 50% (EC50 ) and 95% of the population (EC95 ) required to maintain QTc interval prolongation < 15 ms following intubation was calculated using the isotonic regression and a bootstrapping approach following the Dixon's up-and-down method.

RESULTS

Median duration of hypertension was 6 years. Isotonic regression revealed that the EC50 (83% confidence interval) of remifentanil Ce for reducing QTc interval prolongation following intubation was 3.8 (3.5-4.1) ng/ml in normotensive and 6.1 (5.8-6.2) ng/ml in hypertensive female patients. The EC95 (95% confidence interval) of remifentanil Ce was 4.4 (4.3-4.5) ng/ml in normotensive and 6.5 (6.4-6.5) ng/ml in hypertensive female patients.

CONCLUSION

The Ce of remifentanil required to attenuate QTc interval prolongation following intubation was significantly higher in hypertensive patients than it was in normotensive patients. Thus, more caution should be taken related to QTc interval prolongation when intubating hypertensive patients.

QT Indexes in Cirrhotic Patients: Relationship with Clinical Variables and Potential Diagnostic Predictive Value

BACKGROUND AND AIMS

A wide spectrum of cardiovascular changes characterizes cirrhosis, ranging from subclinical alterations to hyperkinetic syndrome. We looked for ECG markers of ventricular repolarization in a population of patients with cirrhosis in comparison to patients without cirrhosis and we investigated the relationship between these and other clinical and laboratory variables.

METHODS

In 149 patients with cirrhosis and 152 controls, we measured QT maximum interval (QTmax), QT corrected interval (QTc), QT minimum interval (QTmin), QT dispersion (QTdisp), QT peak and T peak-to-end (TpTe).

RESULTS

In subjects with cirrhosis, in comparison with controls, we observed a higher mean QTmax, mean QTc, mean QTmin, mean QTdisp and mean TpTe. At Cox regression analysis, diastolic blood pressure and beta-blocker treatment were significantly associated with mean QTmax, hypertension with mean QTmin and mean QTc, diastolic blood pressure, beta-blockers and ACE-inhibitors/ARBs with QT disp, and beta-blockers with TpTe. Analysis of ROC curves showed a significant area under curve towards cirrhosis diagnosis, respectively, for a cut-off value of > 400 msec of QTmax, > 360 msec of QTmin, > 450 msec of QTc, > 105 msec of TpTe and > 55 msec of QTdisp.

CONCLUSIONS

Our study shows that QT indexes are altered in cirrhotic patients and have a potential diagnostic predictive value.

The relationship between QT dispersion and exaggerated blood pressure response to exercise stress testing

This study was aimed to investigate sensitivity and specificity of QT dispersion (QTd) as a predictor of hypertensive response to peak exercise stress testing (EST). Fifty-nine patients were divided in to two groups (32 patients with exaggerated blood pressure response (EBPR) to EST group and 27 patients for normotensive group) and the EST was monitored. The QTd and corrected QT (QTc) intervals were still found to be significant predictors of EBPR (P < 0.05). In receiver operating characteristic (ROC) analysis, a level of QTd ≥ 40 predicted EBPR with 84% sensitivity and 74% specificity. According to the present data, QTd might be an important predictive marker for EBPR.

Aging modulates dispersion of ventricular repolarization in the very old of the geriatric population

Aging plays an essential role in cardiac pathophysiology. Knowledge on the ventricular repolarization in very old individuals is limited. An increase of QT dispersion is associated with higher cardiovascular mortality. The purpose of this study is to investigate whether aging changes the QT dispersion in the very old. Heart rate, P wave duration, PR interval, QRS axis, QRS duration, QT interval, and QTc interval were measured from 12-lead resting ECG. QT dispersion (46 ± 21, 47 ± 17, 69 ± 31 ms, p < 0.005) was significantly increased in the age group ≧85 years (n = 29, 89 ± 4 years) than in the age group 75-84 years (n = 33, 79 ± 3 years) and the age group 65-74 years (n = 32, 68 ± 3 years). Aging modulates dispersion of ventricular repolarization, which may contribute to the cardiac mortality in the very old Asian population.