Diagnosis of left ventricular diastolic dysfunction in the setting of acute changes in loading conditions.

INTRODUCTION: Conventional pulsed wave Doppler parameters are known to be preload dependent, whereas newly proposed Doppler indices may be less influenced by variations in loading conditions. The aim of the present study was to evaluate the effects of haemodialysis-induced preload reduction on both conventional and new Doppler parameters for the assessment of left ventricular (LV) diastolic function. METHODS: This prospective observational study was conducted in a medical-surgical intensive care unit (ICU) and nephrology department of a teaching hospital. In total, 37 haemodialysis patients with end-stage renal disease (age [mean +/- standard deviation]: 52 +/- 13 years) and eight ventilated ICU patients with acute renal failure receiving vasopressor therapy (age 57 +/- 16 years; Simplified Acute Physiology Score II 51 +/- 17) were studied. Echocardiography was performed before and after haemodialysis. Conventional pulsed wave Doppler indices of LV diastolic function as well as new Doppler indices, including Doppler tissue imaging early diastolic velocities (E' wave) of the septal and lateral portions of the mitral annulus, and propagation velocity of LV inflow at early diastole (Vp) were measured and compared before and after ultrafiltration. RESULTS: The volume of ultrafiltration was greater in haemodialysis patients than in ICU patients (3.0 +/- 1.1 l versus 1.9 +/- 0.9 l; P = 0.005). All conventional pulsed wave Doppler parameters were altered by haemodialysis. In haemodialysis patients, E' velocity decreased after ultrafiltration when measured at the septal mitral annulus (7.1 +/- 2.5 cm/s versus 5.9 +/- 1.7 cm/s; P = 0.0003), but not at its lateral portion (8.9 +/- 3.1 cm/s versus 8.3 +/- 2.6 cm/s; P = 0.37), whereas no significant variation was observed in ICU patients. Vp decreased uniformly after ultrafiltration, the difference being significant only in haemodialysis patients (45 +/- 11 cm/s versus 41 +/- 13 cm/s; P = 0.04). Although of less magnitude, ultrafiltration-induced variations in Doppler parameters were also observed in haemodialysis patients with altered LV systolic function. CONCLUSION: In contrast to other Doppler parameters, Doppler tissue imaging E' maximal velocity measured at the lateral mitral annulus represents an index of LV diastolic function that is relatively insensitive to abrupt and marked preload reduction.

Transesophageal echocardiography and therapeutic management of patients sustaining blunt aortic injuries.

BACKGROUND: No objective criteria have been described to help selecting patients with major blunt aortic injury (BAI) for postponed surgical repair. The efficacy of conservative management of minor BAI needs further evaluation. METHODS: We studied 31 patients (Injury Severity Score, 48 +/- 15) who sustained a BAI diagnosed using transesophageal echocardiography (TEE). In patients with major BAI, the timing of surgery was made on the basis of clinical findings (grade 2) or TEE results (grade 3). We retrospectively separated patients into group I (rapid surgery, < or = 12 hours; n = 13) and group II (late or no surgery; n = 11). All major BAIs were confirmed by alternative imaging modalities or surgery. Patients with minor BAI (grade 1; n = 7) prospectively underwent conservative management with serial TEE follow-up. RESULTS: All patients with grade 3 BAI (n = 4) were promptly operated on. No group II patient died as a result of aortic rupture, and all of them exhibited a small false aneurysm formation (ratio between the maximal diameter of the injured aortic isthmus and the diameter of the normal descending aorta < 1.4) and hemomediastinum (< 7.2 mm). TEE follow-up of group II patients (mean, 5 months) showed stable BAI, whereas follow-up of patients with minor BAI (mean, 15 months) disclosed total healing (n = 3) or stable lesions (n = 4). CONCLUSION: Conservative management of minor BAI with serial follow-up appears to be appropriate. In patients with a grade 2 BAI and small false aneurysm formation and hemomediastinum, postponed surgical repair appears to be safe. However, these TEE criteria remain to be tested prospectively.

Diagnostic ability of hand-held echocardiography in ventilated critically ill patients.

STUDY OBJECTIVES: To compare the diagnostic capability of recently available hand-held echocardiography (HHE) and of conventional transthoracic echocardiography (TTE) used as a gold standard in critically ill patients under mechanical ventilation. DESIGN: A prospective and descriptive study. SETTING: The general intensive care unit of a teaching hospital. PATIENTS: All mechanically ventilated patients requiring a TTE study with a full-feature echocardiographic platform (Sonos 5500; Philips Medical Systems, Andover, MA, USA) also underwent an echocardiographic examination using a small battery-operated device (33 x 23 cm2, 3.5 kg) (Optigo; Philips Medical Systems). INTERVENTIONS: Each examination was performed independently by two intensivists experienced in echocardiography and was interpreted online. For each patient, the TTE videotape was reviewed by a cardiologist experienced in echocardiography and the final interpretation was used as a reference diagnosis. RESULTS: During the study period, 106 TTE procedures were performed in 103 consecutive patients (age, 59 +/- 18 years; Simplified Acute Physiology Score, 46 +/- 14; body mass index, 26 +/- 9 kg/m2; positive end-expiratory pressure, 8 +/- 4 cmH2O). The number of acoustic windows was comparable using HHE and TTE (233/318 versus 238/318, P = 0.72). HHE had a lower overall diagnostic capacity than TTE (199/251 versus 223/251 clinical questions solved, P = 0.005), mainly due to its lack of spectral Doppler capability. In contrast, diagnostic capacity based on two-dimensional imaging was comparable for both approaches (129/155 versus 135/155 clinical questions solved, P = 0.4). In addition, HHE and TTE had a similar therapeutic impact in 45 and 47 patients, respectively (44% versus 46%, P = 0.9). CONCLUSIONS: HHE appears to have a narrower diagnostic field when compared with conventional TTE, but promises to accurately identify diagnoses based on two-dimensional imaging in ventilated critically ill patients.