Pulmonic stenosis, is a dynamic or fixed obstruction of flow from the
right ventricle
A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium (heart), atrium, an adjace ...
of the heart to the
pulmonary artery
A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the ''main pulmonary artery'' or ''pulmonary trunk'' from the heart, and ...
. It is usually first diagnosed in childhood.
Signs and symptoms
Some individuals with mild PS may not experience any symptoms. Mild PS is generally a benign condition that requires regular cardiac follow-up but no specific therapy.
However, there can be symptomatic cases. For example, a systolic ejection murmur, often accompanied by or without a systolic click, can be heard with a stethoscope. Patients may also feel tired easily (especially during physical activity), breathing difficulties (particularly during exertion), discomfort in the chest and lungs, and some individuals may also experience fainting episodes. In severe cases, patients may experience bluish or greyish skin due to low oxygen levels, especially in babies with critical PS.
Cause
Pulmonic stenosis is usually due to isolated valvular obstruction (
pulmonary valve stenosis
Pulmonary valve stenosis (PVS) is a heart valve disorder. Blood going from the heart to the lungs goes through the pulmonary valve, whose purpose is to prevent blood from flowing back to the heart. In pulmonary valve stenosis this opening is too ...
), but it may be due to
subvalvular or supravalvular obstruction, such as
infundibular stenosis. It may occur in association with other
congenital heart defect
A congenital heart defect (CHD), also known as a congenital heart anomaly, congenital cardiovascular malformation, and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital h ...
s as part of more complicated syndromes (for example,
tetralogy of Fallot
Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are:
* Pulmonary stenosis, which is narrowing of the exit from the r ...
).
Pathophysiology
When pulmonic stenosis (PS) is present, resistance to blood flow causes right ventricular hypertrophy. If right ventricular failure develops, right atrial pressure will increase, and this may result in a persistent opening of the
foramen ovale, shunting of unoxygenated blood from the right atrium into the left atrium, and systemic
cyanosis
Cyanosis is the change of Tissue (biology), tissue color to a bluish-purple hue, as a result of decrease in the amount of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Cyanosis is apparent usually in the Tissue (bi ...
. If pulmonary stenosis is severe,
congestive heart failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to fill with and pump blood.
Although symptoms vary based on which side of the heart is affected, HF typically pr ...
occurs, and systemic venous engorgement will be noted. An associated defect such as a
patent ductus arteriosus
Patent ductus arteriosus (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after childbirth, birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs from the aorta, which has a h ...
partially compensates for the obstruction by shunting blood from the left ventricle to the aorta then back to the pulmonary artery (as a result of the higher pressure in the left ventricle) and back into the lungs.
Treatment
The treatment of choice is
percutaneous balloon valvuloplasty
Aortic valvuloplasty, also known as balloon aortic valvuloplasty (BAV), is a procedure used to improve blood flow through the aortic valve in conditions that cause aortic stenosis, or narrowing of the aortic valve. It can be performed in various pa ...
and is done when a resting
peak gradient is seen to be >60mm Hg or a mean >40mm Hg is observed.
References
* Ren (Jul. 15, 2009)
Pulmonic Stenosis ''eMedicine Specialties > Cardiology > Valvular Heart Disease''.
* Hockenberry, M. J., & Wilson, D. (2009). Wong's essentials of pediatric nursing. (8 ed., Vol. 1, p. 872). St. Louis, Missouri: Mosby.
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Valvular heart disease