Bipland Transesophageal Echocardiographic Findings In this case.

Bipland Transesophageal Echocardiographic Findings

In this case, dynamic right ventricular efflux tract obstruction was detected by dint of biplane transesophageal echocardiography in a patient with hemodynamic instability after single-lung transplantation and ventricular septal lack repair.

The utility of transthoracic echocardiography (TTE) for the identification of right and left ventricular flow tract obstruction is well known.[1] The assessment of valvular and subvalvular disease through TTE is reliable and correlates well with angiographic findings. However, because of poor acoustic windows, detection of flow tract obstruction by TTE can be particularly difficult in patients after cardiac surgery The utility of transesophageal echocardiography (TEE) is well documented for the diagnosis of complications after cardiac surgery[2] including the cause of decreased postoperative cardiac output The accuracy of single-plane TEE for characterization of the right ventricular efflux tract (RVOT), pulmonary valve, and pulmonary artery (PA) is limited, however. The addition of the longitudinal plane in biplane TEE provides adequate visualization of these forms so that RVOT obstruction may be identified as a cause of hypotension.

CASE REPORT

A 43-year-old white man was admitted for ventricular septal flaw (VSD) repair and single-lung transplantation. The VSD was diagnosed at age 2 and Eisenmenger's physiology was demonstrated at cardiac catheterization at age 11 He quick in emergenciesed with a 1-year history of progressive dyspnea, hemoptysis, and cough in succession physical examination, the blood press was 130/68 mm Hg, the throb was 80 beats per minute, and the respiratory rate was 20 breaths by minute. The cardiovascular examination revealed flat neck veins, clear lung a right parasternal heave, a prominent secondary heart sound, and a systolic undertone Clubbing and cyanosis were not past nor future The hematocrit was 49 percent swing air arterial blood gas analysis disclosed the following values: pH 747; [PCOsub2] 24 mm Hg; and [POsub2] 51 mm Hg

Cardiac catheterization revealed a right ventricular press of 125/6 mm Hg; PA and pulmonary capillary wedge constraining forces of 125/55 and 4 mm Hg respectively; and normal coronary arteries. Transthoracic echocardiography demonstrated a perimembranous VSD and right ventricular hypertrophy Systolic deliquesce in the PA was 16 m/ consistent with increased sweep along from a VSD and pulmonary hypertension (Fig 1) There was no pulmonary valvular or subvalvular (RVOT) obstruction.

The patient underwent single-lung transplantation with VSD repair and was weaned from cardiopulmonary bypass without difficulties. Low-dose dobutamine, nonrepinephrine bitartrate, and epinephrine were given to maintain cardiac output and vital current pressure. Several hours later, the patient bring to maturityed progressive hypotension and tachycardia. The PA squeezing was 50/15 mm Hg (measured from catheter), with a wedge constraining force of 12 mm Hg and a right atrial influence of 6 mm Hg. Doses of inotropic agents were maximized to little effect

Biplane TEE examination showed marked right ventricular hypertrophy and hyperdynamic right and left ventricular function. There were no regurgitant lesions, extracardiac masses, or thrombi and no pericardial effusion. No switchs were detected by Doppler imaging or upon bubble contrast study. An RVOT obstruction was suspected when a uproarious jet was detected by color-flow imaging across this region (Fig 2) and was verified by way of pullback of the PA catheter, which showed a right ventricular squeezing of 160/9 mm Hg, with a 120 mm Hg gradient across the RVOT

Inotropic agents were discontinued with a dramatic improvement in hemodynamics, as evidenced by way of resolution of systemic hypotension and decreased heart rate (to 88 beats by minute) and right ventricular urgency (to 70/9 mm Hg). kin pressure and cardiac hemodynamics remained stable without inotropic support.

DISCUSSION

Right ventricular efflux tract obstruction has been described in children after spontaneous or operative closure of VSDs[3] usually in patients who instant with a new right-sided continuous sound or symptoms months after correction of a VSD[4] Impedance to emanate at the RVOT is believed to be secondary to an abnormally thickened infundibulum, which forward light and electron microscopy demonstrates hypertrophy bizarre morphology, and myocyte disarray resembling that plant in hypertrophic cardiomyopathy.[5] Presumably, symptoms arise years later because the decrease in follow in the right ventricle after VSD repair leads to a gradual decrease in pulmonary arteriolar resistance, producing an increased gradient. We believe this to be the first report of dynamic RVOT obstruction immediately after VSD repair and single-lung transplantation. principally likely, the dynamic obstruction in this patient ended from the acute reduction in pulmonary arteriolar resistance that happens after single-lung transplantation.[6] Infusion of inotropic agents further exacerbated the dynamic obstruction. In patients with hypertrophic cardiomyopathy, dynamic left ventricular outpouring tract obstruction occurs under conditions of decreased afterload and can be exacerbated by the agency of infusion of inotropic agents. Our patient had no signs or symptoms of outpouring tract obstruction before surgery; as is the case in children who gradually disclose obstruction at rest, there was simply a small gradient ([less than] 12 mm Hg) identified by way of preoperative TTE and right heart catheterization.

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