Systolic time ratio measured by impedance cardiography accurately screens left ventricular diastolic dysfunction in patients with arterial hypertension

Rodrigo Nazário Leão,Marta Alves,Luísa Branco,Roberto Palma Reis,Daniel Virella,Helena Fonseca,Pedro Marques Silva,Bruno Bento

doi:10.1186/s40885-017-0084-y

Abstract

BackgroundThe use of impedance cardiography (ICG) may play a role in the assessment of cardiac effects of hypertension (HT), especially its hemodynamic features. Hypertensive heart disease involves structural changes and alterations in left ventricular geometry that end up causing systolic and/or diastolic dysfunction. The IMPEDDANS study aims to assess the usefulness of ICG for the screening of left ventricular diastolic dysfunction (LVDD) in patients with HT.MethodsPatients with HT were assessed by echocardiography and ICG. Receiver-operating characteristic curve and the area under the curve were used to assess the discriminative ability of the parameters obtained by ICG to identify LVDD, as diagnosed by echocardiography.ResultsICG derived pre-ejection period (PEP), left ventricle ejection time (LVET), systolic time ratio (STR) and D wave were associated (p < 0.001) with LVDD diagnosis, with good discriminative ability: PEP (AUC 0.81; 95% CI 0.74–0.89), LVET (AUC 0.82; 95% CI 0.75–0.88), STR (AUC 0.97; 95% CI 0.94–1.00) and presence of D wave (AUC = 0.87; 95% CI 0.82–0.93). STR ≥ 0.30 outperformed the other parameters (sensitivity of 98.0%, specificity of 90.2%, positive predictive value of 95.2%, and negative predictive value of 96.1%).ConclusionThe ICG derived value of STR allows the accurate screening of LVDD in patients with HT. It might as well be used for follow up assessment.Trial registrationThe study protocol was retrospectively registered as IMPEDDANS on ClinicalTrials.gov (ID: NCT03209141) on July 6, 2017.

Highlights

The use of impedance cardiography (ICG) may play a role in the assessment of cardiac effects of hypertension (HT), especially its hemodynamic features
Patients were excluded in the presence of: pregnancy, height less than 120 cm or more than 230 cm, weight less than 30 kg or greater than 155 kg, heart failure II-IV NYHA, [22] heart rate (HR) less than 50 bpm or greater than 110 bpm, atrial fibrillation or flutter, more than three premature ventricular contractions per hour, complete left bundle branch or atrioventricular block, pacemaker, severe valvulopathy, constrictive pericarditis, hypertrophic and restrictive cardiomyopathy, ischaemic heart disease and/or segmental kinetics anomalies assessed by echocardiography, left ejection fraction
We considered that patients had left ventricular diastolic dysfunction (LVDD) when present septal e’ < 8, lateral e’ < 10 and left atrial volume equal or greater than 34 mL/m2 (Fig. 2) [25]

Summary

Introduction

The use of impedance cardiography (ICG) may play a role in the assessment of cardiac effects of hypertension (HT), especially its hemodynamic features. Diastolic dysfunction is part of this continuum, and despite the growing recognition of its importance, it is Nazário Leão et al Clinical Hypertension (2017) 23:28 characterizing a hypertensive patient’s hemodynamic phenotypic profile and optimizing the antihypertensive therapy [5, 6]. It analyses and registers hemodynamic changes through the measurement of electrical resistance changes in the thorax and translating them graphically as impedance and electrocardiogram waveforms [5, 7, 8]. It is important to have alternative tests for the initial assessment of diastolic function in hypertensive patients

Methods

Results

Discussion

Conclusion