Applanation tonometry application in ICU patients with acute cardiogenic edema

Introduction

The incidence of acute cardiogenic pulmonary edema (ACPE) is increasing and it is now one of the leading causes of morbidity and mortality in our society. As the global population of European countries is getting older, the impact of arterial stiffness is becoming more and more important in the pathophysiology of ACPE, besides coronary vascular disease and valvular disease. The aim of the study was to evaluate whether acute modifications in elastic artery distensibility can be involved in the pathogenesis of ACPE.

Methods

Six consecutive patients (four men and two women; age 76 ± 7.1 years) were admitted to our ICU with the clinical diagnosis of ACPE. All patients were studied with transthoracic echocardiography (TTE) and by evaluation of pulse wave analysis (PWA) and pulse wave velocity (PWV) with the applanation tonometry method, performed at admission and after clinical stabilization.

Results

In all patients, left ventricular systolic function was not significantly reduced when evaluated with transthoracic echocardiography, while a diastolic dysfunction was always demonstrated. We have recorded a significant (P < 0.05) decrease in blood pressure values after clinical stabilization. Estimation of the central aortic pressure waveform by mathematical transformation of radial tonometry pressure was similarly reduced. Other tonometric parameters, such as the Augmentation Index, which represents the contribution of the wave reflection to the global pulse pressure wave, and PWV, which is inversely correlated to the arterial compliance, were also significantly decreased, when compared with the values at the admission time. The subendocardial viability ratio (SEVR), an indirect index of myocardial perfusion relative to cardiac workload, increased after treatment with vasodilatators.

Conclusions

Our data confirm the determining role of the increased arterial stiffness in the pathogenesis of ACPE, and how a therapeutic strategy able to ameliorate this target can be associated with a clinical improvement for the patient. The applanation tonometry could be an interesting method to evaluate these patients in the ICU setting.