Valvular stenosis

Cardiovascular disease. The hypotensive effects of thiopentone are exaggerated in patients with myocardial dysfunction, fixed cardiac output (valvular stenosis, constrictive pericarditis), and in the hypovolaemic... 

Caution should also be exercised in patients with thyrotoxicosis and with valvular stenosis, coronary artery insufficiency (36), or other conditions in which a tachycardia is hazardous. 

Two-dimensional ECHO employs multiple windows of the heart, and each view provides a wedge-shaped image. Windows most commonly used include parasternal long- and short-axis and apical two-and four-chamber views (Fig. 11-6). These views are processed onto a videotape to produce a motion picture of the heart. 2D ECHO renders increased accuracy in calculating ventricular volumes, wall thickness, and degree of valvular stenosis compared with M-mode ECHO. Patient-specific calculated parameters such as ejection fraction and wall thickness are compared with standardized values (population-... 

Formation of vegetations may destroy valvular tissue, and continued destruction can lead to acute heart failure via perforation of the valve leaflet, rupture of the chordae tendineae or papillary muscle, or in the patient with PVE, valve dehiscence. Occasionally, valvular stenosis may occur. Abscesses can develop in the valve ring or in myocardial tissue itself. Even with resolution of the process, fibrosis of tissue with some residual dysfunction is possible. 

Aortic diseases can be classified in aortic enlargement (aneurysms) or tears (dissections) and in either case, the rupture may have fatal results. Aging can lead to atherosclerosis of the aorta with involvement of the aortic valve. This may result in valvular stenosis, regurgitation, aneurysm formation, and acute dissections. 

Heart valve disease occurs when a valve does not work properly. In valvular stenosis, the valve leaflets tissues become stiffer, narrowing the valve opening and reducing the blood flow. If the narrowing is mild, the overall functioning of the heart may not be reduced. However, the valve can become so narrow (stenotic) that heart function is reduced, and the rest of the body may receive inadequate blood flow. Another valvular heart disease condition, called valvular regurgitation, occurs when the leaflets do not close completely, letting blood leak backward across the valve. 

Fig. 19.4a-d. A 57-year-old man with bicuspid aortic valve. MDCT confirms heavy valvular calcifications and demonstrated a narrowed aortic valve orifice indicating severe valvular stenosis (a-c) (see next page)... 

Morino Y, Hara K, Tanabe K, et al. (2000) Retrospective analysis of cerebral complications after coronary artery bypass grafting in elderly patients. Jpn Circ J 64 46-50 Omran H, Schmidt H, Hackenbroch M, et al. (2003) Silent and apparent cerebral embolism after retrograde catheterisation of the aortic valve in valvular stenosis a prospective, randomised study. Lancet 361 1241-1246 Pichler P, Loewe C, Roedler S, et al. (2008) Detection of high-grade stenoses with multi-detector-row computed tomography in heart transplant patients. J Heart Lung Transplant 27 310 316... 

Table 6. Compensation (of equal cardiac output) of a valvular stenosis of 0.6 cm diameter...

Eq. (5) and (6) can be incorporated into the general model discussed here and solved for different values ofA. Table 5 lists the calculated mechanical parameters for different valvular stenosis. Interestingly, the ejection fraction and cardiac output does not change until a critical stenosis is reached. A decrease in the peak flow with increased stenosis is followed by a longer ejection time so as to maintain a constant ejection fraction. The ejection fraction sharply declines once... 

Causes of systolic dysfunction (decreased contractility) are reduction in muscle mass (e.g., myocardial infarction [MI]), dilated cardiomyopathies, and ventricular hypertrophy. Ventricular hypertrophy can be caused by pressure overload (e.g., systemic or pulmonary hypertension, aortic or pulmonic valve stenosis) or volume overload (e.g., valvular regurgitation, shunts, high-output states). 

Decreased cardiac output Heart failure Sepsis Pulmonary hypertension Aortic stenosis (and other valvular abnormalities) Anesthetics... 

Rheumatic mitral valve disease is associated with thromboembolic complications at reported rates of 1.5 to 4.7% per year the incidence in patients with mitral stenosis is approximately 1.5 to 2 times that in patients with mitral regurgitation. The presence of atrial fibrillation is the single most important risk factor for thromboembolism in valvular disease, increasing the incidence of thromboembolism in both mitral stenosis and regurgitation four- to sevenfold. In current practice, patients with nonrheumatic atrial fibrillation at low risk for thromboembolism based on clinical characteristics frequently are treated with aspirin. Warfarin therapy is considered in higher-risk patients, especially those with previous thromboembolism and in whom anticoagulation is not contraindicated due to preexisting conditions. 

Otto CM, Mickel MC, Kennedy JW, et al. Three-year outcome after balloon aortic valvuloplasty, Insights into prognosis of valvular aortic stenosis, Circulation I 994 89(2) 642-650. 

Q13 Arterial emboli, which can block blood vessels and cause ischaemia or infarction in the tissues they affect, tend to originate in the left heart and are associated with valvular disease and dysrhythmias. Mitral stenosis is associated with abnormal atrial rhythm, particularly atrial fibrillation. Fibrillation and other rhythm abnormalities in the atria favour blood coagulation, resulting in production of thromboemboli which can move to distant parts of the circulation, such as the cerebral circulation. Thrombi could also form on surfaces of valves distorted by calcification and other abnormalities. In view of the risks of thromboembolism, it is usual to provide anticoagulant therapy to patients with mitral valve problems and atrial fibrillation. 

Thorough cardiac examination should look for possible cardiac source of embolism, including atrial fibrillation, mitral stenosis and prosthetic heart valves. Left ventricular hypertrophy suggests hypertension or aortic stenosis, and a displaced apex from a dilated left ventricle indicates underlying cardiac or valvular pathology. 

ECHO remains the procedure of choice in the diagnosis and evaluation of a number of conditions such as valvular dysfunction (aortic and mitral stenosis and regurgitation and endocarditis), wall motion abnormalities associated with ischemia, and congenital abnormalities, such as ventricular or atrial septal defects. Images obtained from ECHO are used to estimate chamber wall thickness and left ventricle ejection fraction, assess ventricular function, and detect abnormalities of the pericardium such as effusions or thickening. 

Patients with DHF may present with an acute onset of pulmonary edema. There are a number of potential causes for the acute decompensation of these patients, including volume overload, uncontrolled hypertension, acute myocardial ischemia, progressive valvular disease (aortic stenosis), and new-onset or uncontrolled tachyarrhythmias. Treatment strategies for these patients eventually may include the need for surgery, as in the case of valvular disease. 

Moderate-risk conditions Mitral valve prolapse with valvular regurgitation or leaflet thickening, isolated mitral stenosis, tricuspid-valve disease, pulmonary stenosis, and hypertrophic cardiomyopathy... 

Trace elemeuts were measured iu myocardial and muscle-tissue samples from 13 patieuts diaguosed with idiopathic dilated cardioutyopathy (IDCM). The subjects had no history of Hg exposure. Findings were compared with Hg concentrations measured in n ocardi and muscle biopsies from age-matched patients with valvular (12 patients) or ischemic heart disease (13 patients), papillary and skeletal-muscle biopsies from 10 patients with mitral stenosis, and left-ventricle endomyocardial biopsies from 4 normal subjects. Hg concentrations in myocardial samples collected from patients with IDCM were... 

Population-based echocardiographic studies in the United States estimate that about 2.5% of the population have moderate to severe valvular dysfunction (1). Of the cardiac valvular disease categories reported, mitral regurgitation was found to be the most prevalent (1.7%), followed by aortic regurgitation and stenosis (0.5% and 0.4% respectively), while mitral stenosis was the least common (0.1%). The incidence of heart disease increased with age (0.7% between age 18 and 44 and 13.3% in subjects 75 years or older). There was a 1.36-fold increase in overall adjusted mortality in patients with valvular dysfunction compared to those without (1). 

Against this backdrop, research into less invasive approaches to treat valvular disease has been intensified. In the surgical realm, minimally invasive techniques, with its attendant patient and procedural related limitations, have been tried with some success but traditional valvular operations still remain the norm. At the same time, great strides have been made in percutaneous approaches to treatment of valvular disease. Two valvular disease states in which percutaneous balloon valvuloplasty have had great success are in the treatment of pulmonic stenosis and mitral stenosis. 

In adult patients with single native left-sided history of valvular heart disease, aortic stenosis was the most frequently reported valve lesion in the 2001 Euro Heart... 

Otto CM, Burwash IG, Legget ME, et al. Prospective study of asymptomatic valvular aortic stenosis. Clinical, echocardiographic and exercise predictors of outcome. Circulation 1997 95 2262-70. 

Interventional cardiology no longer refers to just percutaneous coronary procedures. Peripheral vascular procedures are now a well-established part of the armamentarium. Perhaps the most exciting innovation in the interventional domain is percutaneous valvular repair for treatment of aortic stenosis and mitral regurgitation. This area has the potential to be transformative. Finally, in the field of electrophysiology, percutaneous ablation to isolate the pulmonary veins in patients with atrial fibrillation achieves success in the majority of patients. Whether this procedure will replace antiar-rhythmic therapy as a first-line approach remains to be seen, but for time being this approach at the very least can offer dramatic symptomatic relief for debilitated patients. 

Moderate to severe (LVEF < 40%) Left-sided valvular heart disease Mild aortic stenosis Aortic insufficiency Mitral regurgitation Mitral stenosis... 

The drug is found to depress myocardial contractility and hence, may produce hypotension it must be given to patients very cautiously those who are having a clear cut history of heart-failure, valvular disease or aortic stenosis. It possesses an antimuscarinic action on the atrioventricular node which may ultimately negate its direct depressant action on that node. 

Data on the accumulation of 22 1 fatty acids in humans are also available from the work of Svaar who examined autopsy material from 54 hearts selected from Norwegian men, age 20 to 69, who had died suddenly from accidents (Svaar, 1982). These hearts were selected from a larger group on the basis of being without myocardial infarction, severe coronary stenosis, cardiac hypertrophy or valvular disease by macroscopical examination. No focal myocardial lesions were present. A mild to moderate lipidosis was found in 50% of the hearts but this was not correlated with the concentration of 22 1 which was present at less than 1% of the total lipids (Svaar,... 

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