Right Ventricular Function
Right Ventricle
The right ventricle is one of four chambers (two atria and two ventricles) in the human heart. It receives deoxygenated blood from the right atrium via the tricuspid valve, and pumps it into the pulmonary artery via the pulmonary valve and pulmonary trunk.
It is triangular in form, and extends from the right atrium to near the apex of the heart.
Its under surface is flattened, rests upon the diaphragm, and forms a small part of the diaphragmatic surface of the heart.
Its posterior wall is formed by the ventricular septum, which bulges into the right ventricle, so that a transverse section of the cavity presents a semilunar outline.
Its upper and left angle forms a conical pouch, the conus arteriosus, from which the pulmonary artery arises.
A tendinous band, called the tendon of the conus arteriosus, extends upward from the right atrioventricular fibrous ring and connects the posterior surface of the conus arteriosus to the aorta.
The left ventricular wall is three times the thickness of the right. The right ventricle wall is thickest at the base and thins towards the apex.
The upper left corner of the right ventricle, where the deoxygenated blood is pumped into the pulmonary artery, is called the infundibulum or conus arteriosus.
The cavity equals in size that of the left ventricle, and contains roughly 85 millilitres (3 imp fl oz; 3 US fl oz) in a normal adult.
Right Ventricular Function
Patients with right coronary artery disease may be susceptible to right ventricular ischemia and infarction when right ventricular distension or increased afterload occurs resulting in diminished cardiac performance and reduced right coronary perfusion pressure. The interrelationships of aortic end-diastolic pressure, afterload volume, coronary perfusion pressure, and pulmonary vascular resistance, play a significant role in the management of right sided cardiac performance. Assessment of these variables prior to treatment is essential in order to avoid compromised function.
Common treatment for systemic hypotension in the period prior to initiating cardiopulmonary bypass incorporates the use of phenylephrine, an ð1-adrenergic agonist. Indication for use is primarily for hypotension induced by a reduction in systemic vascular resistance (SVR) as opposed to compromised cardiac output. The perceived advantage of utilizing phenylephrine is its’ impact on increasing coronary perfusion pressure while having minimal chronotropic side effect.
References
Tuman KJ, McCarthy RJ, March RJ, Guynn TP, Ivankovitch AD. Effects of phenylphrine or volume loading on right ventricular function in patients undergoing myocardial revascularization. Journal of Cardiothoracic and Vascular Anesthesia. 1995;9:2-8.
