Loading conditions influence reliability of the echocardiographic RAMP test in continuous-flow left ventricular assist devices
2013; Elsevier BV; Volume: 32; Issue: 11 Linguagem: Inglês
10.1016/j.healun.2013.06.027
ISSN1557-3117
AutoresSirtaz Adatya, Carolina Masri, Ranjit John, Peter Eckman,
Tópico(s)Cardiac Arrest and Resuscitation
ResumoThromboembolic events are a feared complication after implantation of left ventricular assist devices (LVADs), and confirming the diagnosis of such events can be a challenge. Uriel et al 1 Uriel N. Morrison K.A. Garan A.R. et al. Development of a novel echocardiography ramp test for speed optimization and diagnosis of device thrombosis in continuous-flow left ventricular assist devices: the Columbia Ramp Study. J Am Coll Cardiol. 2012; 60: 1764-1775 Abstract Full Text Full Text PDF PubMed Scopus (251) Google Scholar recently described a novel, echocardiography-monitored speed ramp test in patients with an implanted HeartMate II LVAD. The test can be used to both optimize device speed at discharge and evaluate suspected device obstruction. In this protocol (Table 1), LVAD speed is lowered to minimal support, followed by a stepwise increase in revolutions per minute (rpm). Under optimal loading conditions and with no obstruction to flow, a direct linear relationship between LVAD speed and left vertricular end-diastolic dimension (LVEDD) should be observed. Specifically, unloading of the left ventricle with increasing speed should decrease LVEDD, reduce the severity of mitral regurgitation, and decrease the interval opening of the aortic valve (AV). Results from a prospective cohort suggest that an LVEDD/speed slope >−0.16 was strongly associated with significant obstruction to flow in patients whose clinical presentation was already suggestive of the condition. 1 Uriel N. Morrison K.A. Garan A.R. et al. Development of a novel echocardiography ramp test for speed optimization and diagnosis of device thrombosis in continuous-flow left ventricular assist devices: the Columbia Ramp Study. J Am Coll Cardiol. 2012; 60: 1764-1775 Abstract Full Text Full Text PDF PubMed Scopus (251) Google Scholar Table 1Summary of Speed Ramp Test Protocol for Patients With a HeartMate II LVAD a See Uriel et al1 for a more detailed description of the protocol. Major steps Protocol specifics Pre-test safety assessment Patient must have adequate anticoagulation (international normalization ratio >1.8 or partial thromboplastin time >60 seconds) and show no evidence of intraventricular or aortic root thrombosis by transthoracic echocardiography. Ramp up LVAD speed is lowered to 8,000 revolutions per minute (rpm), then increased by 400 rpm at 2-minute intervals up to 12,000 rpm. Measurements Recordings are taken at baseline and at each speed change for the following: •Device parameters (pulsatility index, power, flow) •Mean arterial blood pressure (MAP) •Echocardiographic measurements of interval of aortic valve (AV) opening, z estimation of aortic and mitral regurgitation, right ventricular systolic pressure, interventricular septal position and left ventricular end-diastolic dimension (LVEDD) Safety assessments during testing Test is stopped if LVEDD <3.0 cm, suction event and or arrhythmias a See Uriel et al 1 Uriel N. Morrison K.A. Garan A.R. et al. Development of a novel echocardiography ramp test for speed optimization and diagnosis of device thrombosis in continuous-flow left ventricular assist devices: the Columbia Ramp Study. J Am Coll Cardiol. 2012; 60: 1764-1775 Abstract Full Text Full Text PDF PubMed Scopus (251) Google Scholar for a more detailed description of the protocol. Open table in a new tab ErratumThe Journal of Heart and Lung TransplantationVol. 33Issue 6PreviewLoading conditions influence reliability of the echocardiographic RAMP test in continuous-flow left ventricular assist devices, Adataya S, Masri C, John R, Eckman P. J Heart Lung Transplant. 2013;32(11):1142-4. Full-Text PDF
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