What is the cause of central cyanosis in Osler-Weber-Rendu syndrome?
Central cyanosis in Osler-Weber-Rendu syndrome is due to pulmonary arteriovenous fistula. Those with Osler-Weber-Rendu syndrome or hereditary hemorrhagic telangiectasia have multiple capillary hemangiomas on skin, lips, mucosa of nose, upper and lower respiratory tract and gastrointestinal tract. Central cyanosis can occur when there are multiple pulmonary arteriovenous fistulae with significant right to left shunt allowing desaturated blood to reach the systemic circulation. (Source: Cardiophile MD)
Source: Cardiophile MD - November 5, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What causes a prominent a wave in jugular venous pulse?
Prominent a wave occurs when the right atrial contraction is more forceful due to increased resistance to right atrial emptying. This occurs in right ventricular hypertrophy, pulmonary hypertension, and tricuspid stenosis. In pulmonary stenosis with right ventricular hypertrophy, prominent a wave would suggest intact interventricular septum. Prominent a wave will be absent in the presence of associated unrestrictive ventricular septal defect. This is because an unrestrictive VSD prevents right ventricular pressure from rising to suprasystemic levels. Prominent a wave can be associated with a presystolic hepatic pulsation....
Source: Cardiophile MD - November 5, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
When does the y descent in jugular venous pulse occur?
y descent in jugular venous pulse occurs with decline of right atrial pressure when the tricuspid valve opens. Slow y descent is seen tricuspid stenosis. Very prominent y descent or Friedreich’s sign occurs in constrictive pericarditis as the right ventricle is not able to expand well during ventricular diastole. (Source: Cardiophile MD)
Source: Cardiophile MD - November 4, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What happens to the amplitude of jugular venous pulsations in inspiration?
Jugular venous pressure normally declines during inspiration, but the amplitude of the pulsations increases. An inspiratory increase in jugular venous pressure is called Kussmaul sign, typical of chronic constrictive pericarditis. (Source: Cardiophile MD)
Source: Cardiophile MD - November 4, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
In which situations are stress echocardiography useful?
Stress echocardiography is useful when exercise stress test is not feasible due to mobility issues. Stress echocardiography is usually done with dobutamine infusion to stress the myocardium. An important emerging role is in patients being prepared for liver transplantation. They are too sick for a treadmill exercise ECG. Invasive coronary angiography which is another alternative is not ideal due to the coagulation defect in such patients. Stress echocardiography is also useful when exercise ECG is not interpretable due to left bundle branch block. Another important role for stress echocardiography is when hibernating myoc...
Source: Cardiophile MD - November 3, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is the maximum speed at which BP cuff can be deflated while measuring blood pressure?
Maximum speed at which BP cuff can be deflated while measuring blood pressure is 3 mm Hg/second. If the cuff is rapidly deflated, the blood pressure measurement error will be high. Initial inflation of cuff should be rapid and about 30 mm Hg above the anticipated blood pressure. Cuff should be deflated fully after measuring diastolic pressure for at least one minute before a repeat measurement is attempted. (Source: Cardiophile MD)
Source: Cardiophile MD - November 3, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is the mechanism of decubitus angina?
Increase in venous return and consequent increase in preload on assuming the supine position is the reason for decubitus angina. Most likely these patients have severe multivessel coronary artery disease or critical narrowing of a major coronary branch. (Source: Cardiophile MD)
Source: Cardiophile MD - November 3, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Why is angina not a typical symptom of left ventricular aneurysm?
Angina pectoris indicates viable but ischemic myocardium. In ventricular aneurysm, it is usually a non-viable scarred area of myocardium, due to poorly collateralized chronically occluded coronary artery. The border zone of the aneurysm is vulnerable to form re-entrant circuits which can trigger ventricular tachycardia. As the aneurysmal segment bulges out in systole instead of contracting, the systolic effort of the left ventricle is wasted. Part of the effort of the remaining left ventricular muscle is wasted in moving blood in and out of the aneurysm pouch. This leads to heart failure. Mural thrombi can form in th...
Source: Cardiophile MD - November 3, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What are the mechanical complications of acute myocardial infarction?
Typical mechanical complications of acute myocardial infarction are rupture of papillary muscle, rupture of interventricular septum and rupture of left ventricular free wall. Mechanical complications are more life threatening and seldom respond to medical management. They need early high risk surgery. Rupture of papillary muscle causes severe acute mitral regurgitation and pulmonary edema. Rupture of interventricular septum produces an acquired ventricular septal defect and leads to severe heart failure. Rupture of ventricular free wall causes hemopericardium and cardiac tamponade. (Source: Cardiophile MD)
Source: Cardiophile MD - November 3, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What are percussion wave and tidal wave?
Percussion wave and tidal wave are the waves seen on a pulse tracing. Reflected wave from the periphery is thought to be the mechanism behind the tidal wave which occurs after the percussion wave which is due to the direct transmission of the left ventricular ejection. Percussion wave is noted mainly in the central aorta, brachiocephalic and carotid arteries. Usually percussion wave is taller than the tidal wave. But in the elderly with increased peripheral resistance, the tidal wave may be taller so that the pulse may peak later in systole. (Source: Cardiophile MD)
Source: Cardiophile MD - November 3, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
In which condition is a hyperkinetic pulse associated with a normal pulse volume?
Hyperkinetic pulse usually has a high pulse volume but in hypertrophic obstructive cardiomyopathy, is it associated with a normal pulse volume. A hyperkinetic pulse in HOCM is due to rapid initial rate of development of left ventricular pressure. Volume is not high because left ventricular outflow obstruction sets in soon. A hyperkinetic pulse with normal pulse volume may also be noted in mitral regurgitation. Here again the dilated left ventricle empties rapidly, but volume is not high because part of the blood goes back into the left atrium and not the aorta. In all other conditions with hyperkinetic puls...
Source: Cardiophile MD - November 3, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is the commonest site of RVOT obstruction in TOF?
What is the commonest site of right ventricular outflow tract obstruction in tetralogy of Fallot? The commonest site of right ventricular outflow obstruction in Tetralogy of Fallot is infundibular (subvalvar) pulmonary stenosis. Obstruction can be at other locations like valvar pulmonary stenosis, supravalvar pulmonary stenosis and annular pulmonary stenosis. There could be a combination of these lesions as well. Infundibular spasm with dynamic worsening of right ventricular outflow obstruction is thought to be one of the pathophysiological mechanisms of cyanotic spells in Tetralogy of Fallot. Immature respirat...
Source: Cardiophile MD - November 3, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is a continuous murmur?
Continuous murmur is not a murmur which is continuously heard throughout systole and diastole, though some like the murmur patent ductus arteriosus is like that. By definition, a continuous murmur begins in systole and continues without interruption, through the second heart sound into diastole. It can cover either part of diastole or the whole of diastole. A murmur which disappears completely before the next first heart sound is still considered continuous if the systolic part continues without interruption during the second heart sound. Highest intensity of continuous murmur is usually heard in rupture of sinus of Valsa...
Source: Cardiophile MD - November 2, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is myocardial contrast echocardiography?
Myocardial contrast echocardiography (MCE) is used for the assessment of myocardial microcirculation and endocardial demarcation. MCE uses gas-filled microbubbles that are inert and remain wholly within the vascular space. These microbubbles have an intravascular rheology similar to that of red blood cells [1]. A continuous intravenous infusion of microbubbles is given to achieve a steady state. These microbubbles are destroyed by high energy ultrasound. The rate of microbubble replenishment within the ultrasound beam is measured and represents the mean red blood cell velocity [2].
Normally, the ultrasound beam fills with...
Source: Cardiophile MD - November 1, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is arterial switch operation for TGA? Cardiology Basics
Arterial switch operation is the ideal corrective surgery for transposition of great arteries (TGA). It was described by Jatene and colleagues in 1976. Normally aorta originates from the left ventricle and pulmonary artery originates from the right ventricle. This is reversed in TGA, so that pulmonary artery arises from the left ventricle and aorta originates from the right ventricle. Arterial switch operation normalizes this relationship, by moving the aorta and pulmonary artery back to their expected positions.
When the blood vessels are switched, the coronary arteries are also repositioned to arise from the new aorta w...
Source: Cardiophile MD - October 28, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
