Phonocardiograms from normal and abnormal heart sounds Simultaneous left ventricular and aortic pressure tracings to demonstrate a pressure gradient between the left ventricle and aorta, suggesting<unk> . The left ventricle generates higher pressures than what is transmitted to the aorta. The pressure gradient, caused by<unk> , is represented by the green shaded area. (AO = ascending aorta; LV = left ventricle; ECG = electrocardiogram.) Palpation<unk>  is most often diagnosed when it is asymptomatic and can sometimes be detected during routine examination of the heart and circulatory system. Good evidence exists to demonstrate that certain characteristics of the peripheral pulse can rule in the diagnosis. In particular, there may be a slow and/or sustained upstroke of the arterial pulse, and the pulse may be of low volume. This is sometimes referred to as pulsus parvus et tardus. There may also be a noticeable delay between the first heart sound (on auscultation) and the corresponding pulse in the carotid artery (so-called 'apical-carotid delay'). In a similar manner, there may be a delay between the appearance of each pulse in the brachial artery (in the arm) and the radial artery (in the wrist). Auscultation The first heart sound may be followed by a sharp ejection sound ("ejection click") best heard at the lower left sternal border and the apex, and, thus, appear to be "split". The ejection sound, caused by the impact of left ventricular outflow against the partially fused aortic valve leaflets, is more commonly associated with a mobile bicuspid aortic valve than an immobile calcified aortic valve. The intensity of this sound does not vary with respiration, which helps distinguish it from the ejection click produced by a stenotic pulmonary valve, which will diminish slightly in intensity during inspiration. An easily heard systolic, crescendo-decrescendo (i.e., 'ejection') murmur is heard loudest at the upper right sternal border, at the 2nd right intercostal space, and radiates to the carotid arteries bilaterally. The murmur increases with squatting and decreases with standing and isometric muscular contraction such as the Valsalva maneuver, which helps distinguish it from hypertrophic obstructive cardiomyopathy (HOCM). The murmur is louder during expiration but is also easily heard during inspiration. The more severe the degree of the stenosis, the later the peak occurs in the crescendo-decrescendo of the murmur. The second heart sound (A2) tends to become decreased and softer as the<unk>  becomes more severe. This is a result of the increasing calcification of the valve preventing it from "snapping" shut and producing a sharp, loud sound. Due to increases in left ventricular pressure from the stenotic aortic valve, over time the ventricle may hypertrophy, resulting in diastolic dysfunction. As a result, there may be a fourth heart sound due to the stiff ventricle. With continued increases in ventricular pressure, dilatation of the ventricle will occur, and a third heart sound may be manifest. Finally,<unk>  often co-exists with some degree of aortic insufficiency (aortic regurgitation). Hence, the physical exam in<unk>  may also reveal signs of the latter, for example, an early diastolic decrescendo murmur. Indeed, when both valve abnormalities are present, the expected findings of either may be modified or may not even be present. Rather, new signs that reflect the presence of simultaneous<unk>  and insufficiency, e.g., pulsus bisferiens, emerge. According to a meta-analysis, the most useful findings for ruling in<unk>  in the clinical setting were slow rate of rise of the carotid pulse (positive likelihood ratio ranged 2.8–130 across studies), mid to late peak intensity of the murmur (positive likelihood ratio, 8.0–101), and decreased intensity of the second heart sound (positive likelihood ratio, 3.1–50). Other peripheral signs include: * sustained, heaving apex beat, which is not displaced unless systolic dysfunction of the left ventricle has developed * A precordial thrill * narrowed pulse pressure Electrocardiogram Although<unk>  does not lead to any specific findings on the electrocardiogram (ECG), it still often leads to a number of electrocardiographic abnormalities. ECG manifestations of left ventricular hypertrophy (LVH) are common in<unk>  and arise as a result of the stenosis having placed a chronically high-pressure load on the left ventricle (with LVH being the expected response to chronic pressure loads on the left ventricle no matter what the cause). As noted above, the calcification process that occurs in<unk>  can progress to extend beyond the aortic valve and into the electrical conduction system of the heart. Evidence of this phenomenon may rarely include ECG patterns characteristic of certain types of heart block such as Left bundle branch block. Heart catheterization Cardiac chamber catheterization provides a definitive diagnosis, indicating severe stenosis in valve area of 2 (normally about 3 cm2). It can directly measure the pressure on both sides of the aortic valve. The pressure gradient may be used as a decision point for treatment. It is useful in symptomatic people before surgery. The standard for diagnosis of<unk>  is non-invasive testing with echocardiography. Cardiac catheterization is reserved for<unk> es in which there is a discrepancy between the clinical picture and non-invasive testing, due to risks inherent to crossing the aortic valve, such as stroke. Echocardiogram Severity of<unk>  Degree Mean gradient (mmHg) Aortic valve area (cm2) Mild 1.5 Moderate 25 - 40 1.0 - 1.5 Severe >40 70 Gradient = 4(velocity)² mmHg A normal aortic valve has a gradient of only a few mmHg. A decreased valvular area causes increased pressure gradient, and these parameters are used to classify and grade the<unk>  as mild, moderate or severe. The pressure gradient can be abnormally low in the presence of mitral stenosis, heart failure, co-existent aortic regurgitation and also ischaemic heart disease (disease related to the decreased blood supply and oxygen causing ischemia). Echocardiogram may also show left ventricular hypertrophy, thickened and immobile aortic valve, and dilated aortic root. However, it may appear deceptively normal in acute<unk> es. Chest X-ray A chest X-ray can also assist in the diagnosis and provide clues as to the severity of the disease, showing the degree of calcification of the valve, and in a chronic condition, an enlarged left ventricle and atrium. Computer tomography The use of CT calcium scoring is gaining spread as a diagnostic tool to complement echo in the assessment of patients with<unk> .
Aortic stenosis
Hypertrophic cardiomyopathy
Mitral stenosis
Aortic regurgitation
Tricuspid valve stenosis
Tricuspid regurgitation
Mitral regurgitation
Pulmonary valve stenosis