Echocardiographic evaluation of right ventricle function with tissue doppler after spinal anesthesia [evaluación ecocardiográfica de la función del ventrículo derecho con doppler tisular luego de una anestesia espinal]

The function of the right ventricle (RV), for years forgotten, is an important predictor of perioperative morbidity and mortality, so its evaluation is fundamental. The irregular morphology of it makes difficult the use of geometric echocardiographic models classically used with the Left Ventricle (LV). Echocardiographic indices have been studied to diagnose RV dysfunction in non-cardiac surgery, such as tricuspid annular systolic excursion (TAPSE), with good correlation with Magnetic Nuclear Resonance (MRI). Lately, the s' wave measurement of the RV has been validated by Tissue Doppler (TDI) to objectify its functionality. A value s' greater than 9.5 cm/sec is defined as normal, having a good correlation with the clinic and TAPSE measured by the same operator. This index has advantages such as being less operator dependent, faster to obtain and with good reproducibility, however, there are no studies that evaluate the effectiveness of this parameter independently. Objectives: To evaluate the diagnostic capacity of the s' wave in a clinical situation that is known to cause RV dysfunction, such as Spinal Anesthesia (SA). Materials and Methods: A prospective study in which ASA I patients older than 18 years were included, assigned to non-cardiac elective surgery with SA. Baseline measurements of heart rate (HR), mean arterial pressure (MAP) and s' wave were made prior SA. After the intrathecal administration of 0.75% Bupivacaine and Fentanyl, a control of the same variables was performed. For the measurement of wave s' (cm/sec) a transthoracic cardiac probe (1 to 5 MHz) was used in apical window 4 cameras at the level of the tricuspid ring. results: 57 patients were recruited (44% women and 56% men). In all patients, there was a decrease in both MAP (85 ± 9 mmHg to 74 ± 7 mmHg) (p < 0.01) and HR (from 78 ± 12 beats per minute [bpm] to 61 ± 9 bpm) (p < 0.01). The decrease in the preload associated with the SA was reflected in a reduction in the wave speed s' from 11.5 + 5.8 cm/sec before SA to 9.8 + 5.1 cm/sec (p < 0.01). Conclusions: For years the intraoperative evaluation of the LV has been given greater importance, however, the function of the RV can also be important to consider since this is where the LV preload will be generated. The present work demonstrates that the SA, causes a compromise of RV function evidenced as a descent of the s' wave.