When do you consider workup for hyperaldosteronism?
Important situation in which hyperaldosteronism is suspected is when there is hypertension with hypokalemia. Hypertension with spontaneous as well as diuretic induced hypokalemia may be an indication of hyperaldosteronism. Another reason for workup is refractory hypertension in spite of three antihypertensive medications. Hypertensive patient having hypokalemia while on angiotensin converting enzyme inhibitors or angiotensin receptor blockers should also alert us.
Yet another group is hypertensives with adrenal masses detected on imaging studies. First degree relatives of patients with primary hyperaldosteronism need work...
Source: Cardiophile MD - November 12, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Apple Heart Study – Clinical Trial Review
Apple Heart Study – Clinical Trial Review
The Apple Heart Study was designed as a large-scale, app-based study to identify cardiac arrhythmias using a smartwatch [1]. Pulse rate can be measured using smartwatch and fitness band wearable consumer electronic devices by photoplethysmography. Pulse irregularity from these data can potentially identify atrial fibrillation.
Participants without self reported atrial fibrillation used a smartwatch (Apple iPhone) app to consent to monitoring. If possible atrial fibrillation was detected by the smartwatch algorithm, a telemedicine visit was initiated and an ECG patch was maile...
Source: Cardiophile MD - November 12, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What are high pass filter and low pass filter in ECG settings?
High pass filters allow only frequencies above the set limit to pass through and hence eliminate components below a particular frequency. For surface ECG, the high pass filter is usually set at 0.05 Hertz in order to preserve the T wave and eliminate baseline drift, typically due to respiration.
Low pass filters on the other hand allow only frequencies below the set limit to pass through and hence eliminate components above a particular frequency. Often it is kept at 40 Hertz to reduce high frequency artifacts due to pick of muscle potential or electromyogram. As a tradeoff, it will often remove pacing artifacts which are...
Source: Cardiophile MD - November 9, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Does stress cardiomyopathy recur?
Though stress cardiomyopathy is a reversible condition, recurrence is known. Average recurrence rate is about 2% to 4% per year. Recurrence as early 4 days and as late 10 years has been documented in literature. Up to 20% recurrence over 10 years is known. Sometimes the recurrent episode may be a different anatomical variant. It may be noted that different variants are apical ballooning (classical Takotsubo pattern), global hypokinesia, mid ventricular variety, variant with left ventricular outflow tract obstruction and mitral regurgitation. Left ventricular outflow obstruction occurs due to basal hypercontractility and m...
Source: Cardiophile MD - November 7, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Why is there a risk of cerebral hypoxia with ECMO?
Venoarterial extracorporeal membrane oxygenator or ECMO is a potential lifesaving intervention in those with refractory cardiogenic shock. But there is a potential risk of cerebral hypoxia because of upper body hypoxemia. Upper body is perfused by the left ventricular output which can be hypoxemic if there is pulmonary edema. Lower body is perfused with oxygenated blood from the ECMO [1].
Reference
Rab T, Ratanapo S, Kern KB, Basir MB, McDaniel M, Meraj P, King SB 3rd, O’Neill W. Cardiac Shock Care Centers: JACC Review Topic of the Week. J Am Coll Cardiol. 2018 Oct 16;72(16):1972-1980. (Source: Cardiophile MD)
Source: Cardiophile MD - November 6, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Awake ECMO
Extracorporeal membrane oxygenation (ECMO) is used for treatment of severe respiratory or cardiopulmonary failure. Usually these patients are sedated and mechanically ventilated, though at lower tidal volumes to reduce lung injury and permit lung recovery.
The concept of Awake ECMO is to do away with mechanical ventilation permitting the patient to eat, drink, sit up and even possibly walk. They can also participate in physiotherapy. One situation in which it is considered is in those who are in bridge to transplantation situation. One study documented 6 month survival after lung transplantation as 80% in the awake ECMO g...
Source: Cardiophile MD - November 6, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is the relation between the resistance of a blood vessel and its radius?
Relation between the resistance of a blood vessel and its radius is governed according to Poiseuille’s Law. If vessel radius decreases, resistance increases by its 4th power. In systemic vascular tree, most of the resistance is contributed by vessels of diameter in the range of 50 – 200 microns. The tone of these resistance vessels is well regulated by humoral and neural influences. Neurally mediated vasoconstriction is through alpha adrenergic receptors on vascular smooth muscle. Vasodilatation is by muscarinic and beta 2 adrenoceptors. (Source: Cardiophile MD)
Source: Cardiophile MD - November 6, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What cardiac lesion can be associated with external ophthalmoplegia?
External ophthalmoplegia and ptosis may be associated with complete heart block. External ophthalmoplegia and ptosis as part of Kearns-Sayre syndrome is associated with complete heart block. It is a muscular dystrophy involving extraocular muscles. (Source: Cardiophile MD)
Source: Cardiophile MD - November 6, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is ascites precox?
The early occurrence of ascites in chronic constrictive pericarditis even before the appearance of generalised edema has been called ‘ascites precox’. Though ascites can occur in any severe long standing heart failure, it is most likely to occur in constrictive pericarditis and severe tricuspid valve disease. (Source: Cardiophile MD)
Source: Cardiophile MD - November 5, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is the usual difference between jugular venous pressure and right atrial pressure and why?
Usually right atrial pressure is more than jugular venous pressure by 5 cm of water. Jugular venous pressure is measured as so many cm above the sternal angle which is the reference point for JVP. Centre of right atrium is usually 5 cm below the sternal angle. Hence if the JVP is 5 cm, right atrial pressure will be 10 cm. Reference point for measurement of central venous pressure using manometer or transducer is the mid thoracic level. Hence measured CVP is usually equal to the right atrial pressure. (Source: Cardiophile MD)
Source: Cardiophile MD - November 5, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
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
