Assessment of right ventricular function postretrograde cardioplegia by transesophageal echocardiography

Efficient myocyte gene delivery with complete cardiac surgical isolation in situ

BACKGROUND

Previously, we used cardiopulmonary bypass with incomplete cardiac isolation and antegrade administration of vector for global cardiac gene delivery. Here we present a translatable cardiac surgical procedure that allows for complete surgical isolation of the heart in situ with retrograde (through the coronary venous circulation) administration of both vector and endothelial permeabilizing agents to increase myocyte transduction efficiency.

METHODS

In 6 adult dogs the heart was completely isolated with tourniquets placed around both vena cavae and cannulas and all pulmonary veins. On cardiopulmonary bypass, the aorta and pulmonary artery were crossclamped, and the heart was isolated. Crystalloid cardioplegia at 4 degrees C containing 10(13) particles of adenovirus encoding LacZ and 15 microg of vascular endothelial growth factor was infused retrograde into the coronary sinus and recirculated for a total of 30 minutes. The dogs were then weaned from cardiopulmonary bypass and allowed to recover. With a catheter, 3 control dogs underwent retrograde infusion of the same cocktail without cardiac isolation or cardiopulmonary bypass.

RESULTS

Beta-galactosidase activities in the cardiopulmonary bypass group were several orders of magnitude higher in both the right and left ventricles when compared with those in the control group (P < .05). X-gal staining from the cardiopulmonary bypass group showed unequivocal evidence of myocyte gene expression globally in a significant proportion of cardiac myocytes. No myocyte gene expression was observed in the control group.

CONCLUSION

A novel cardiac surgical technique has been developed. This approach with cardiac isolation and retrograde delivery of vector through the coronary sinus results in efficient myocyte transduction in an adult large animal in vivo.

A technique for infusion of cardioplegic solution in coronary artery bypass with aortic regurgitation

BACKGROUND

Complications such as heart failure due to insufficient cardioplegia may develop in on-pump coronary artery bypass (CAB) with mild-to-moderate aortic regurgitation (AR). A technique for administration of cardioplegic solution was carried out to avoid such complications.

METHODS AND RESULTS

Cardiopulmonary bypass was established. After aortic cross-clamping, cardioplegic solution was administered from aortic root. Because complete cardiac arrest was not rapidly achieved, the aortic root was incised. Three cusps of the aortic valve were sutured. The aorta was closed; cardioplegic solution was administered from the aortic root. Then, cardiac arrest was rapidly achieved. After distal anastomosis of quadruple bypass was completed, the suture of the cusps was removed. There was no exacerbation of AR due to this method compared to the preoperative state.

CONCLUSION

When off-pump coronary artery bypass is impossible and retrograde cardioplegia cannot be performed for a certain reason, this method may be set to one of the choices.

Determination of right ventricular function by transesophageal echocardiography: impact of proximal right coronary artery stenosis

STUDY OBJECTIVE

To investigate whether transesophageal echocardiography (TEE) can provide accurate information on right ventricular (RV) function in patients with right coronary artery (RCA) stenosis, given that a decrease in blood supply from the RCA may invalidate the use of single 2-D echocardiography imaging plane as a guide to RV function.

DESIGN

Prospective, nonblinded study.

SETTING

University hospital.

PATIENTS

30 adult patients undergoing elective cardiac or vascular procedures.

INTERVENTIONS

Patients were classified into two groups according to the presence or absence of the proximal RCA (segment 1 or 2) stenosis. Group A patients had no obstructive lesions in the proximal RCA (n = 15). Group B patients had 75% or greater obstructive lesions in the proximal RCA (n = 15).

MEASUREMENTS AND MAIN RESULTS

After induction of anesthesia, RV function was evaluated by both fast-response thermodilution pulmonary artery catheter and TEE. Transesophageal echocardiography-derived RV fractional area change (FAC) and tricuspid annular plane systolic excursion ratio (TAPSE ratio) were compared with thermodilution-derived RV ejection fraction (EF) using linear regression analysis. Transesophageal echocardiography-derived RV end-diastolic area (EDA) was compared with thermodilution-derived end-diastolic volume (EDV). Both methods showed a good correlation in RV, EDV, and EF in Group A, but no correlations in Group B.

CONCLUSIONS

Transesophageal echocardiography does not provide reliable information on RVEF and EDV when proximal RCA stenosis is present.