Non-vitamin K antagonist oral anticoagulants (NOACs) and valvular heart disease with AF
Subgroup analysis of certain clinical trials support the use of rivaroxaban, apixaban, dabigatran and edoxaban in patients with aortic stenosis, aortic regurgitation or mitral regurgitation having atrial fibrillation. NOACs can also be used in aortic bioprosthesis with atrial fibrillation if the valve has been implanted more than 3 months back.
NOACs are better avoided in those with moderate or severe mitral stenosis and atrial fibrillation in view of high thromboembolic risk. NOACs should not be used in those with mechanical prosthetic valve with or without atrial fibrillation. Those patients still require vitamin K anta...
Source: Cardiophile MD - November 17, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What are the statin adverse effects with confirmed causality?
Statin adverse effects with confirmed causality, though rare are:
a) Myalgia/myopathy
b) Temporary elevation of alanine aminotransferase
c) New onset diabetes mellitus
Reference
Banach M et al; International Lipid Expert Panel (ILEP). The Role of Nutraceuticals in Statin Intolerant Patients. J Am Coll Cardiol. 2018 Jul 3;72(1):96-118. doi: 10.1016/j.jacc.2018.04.040. PMID: 29957236. (Source: Cardiophile MD)
Source: Cardiophile MD - November 16, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
In what conditions are descending aortic flow reversal seen on Doppler echo?
Descending aortic flow reversal can be noted in aortic regurgitation, rupture of sinus of Valsalva into right ventricle and patent ductus arteriosus. It may be noted that transient descending thoracic aortic flow reversal may be detectable by Doppler echo without any of these conditions.
When the aortic wall is stiff as in hypertensives with atherosclerosis, transient flow reversal is thought to be one mechanism for cerebral embolism from aortic plaques beyond the origin of cerebral vessels.
In severe aortic regurgitation it is a pan diastolic flow reversal with end diastolic velocity more than 20 cm/s. It is taken as an ...
Source: Cardiophile MD - November 16, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is the Effect of venoarterial ECMO on LV afterload?
Venoarterial extracorporeal membrane oxygenation or VA-ECMO increases left ventricular afterload. VA-ECMO is used as a mechanical circulatory support for cardiogenic shock. But it results in increased left ventricular afterload which can have deleterious effects like myocardial ischemia, delayed left ventricular recovery, ventricular arrhythmias and pulmonary edema.
Several interventions have been used to unload the left ventricle during VA-ECMO. The most commonly used strategy is intra-aortic balloon pump or IABP. Other less frequently used methods are percutaneous left ventricular assist device and pulmonary vein or tra...
Source: Cardiophile MD - November 14, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Which chemotherapeutic agent is well known to cause coronary vasospasm?
5-fluorouracil is well known to cause coronary vasospasm. 5-fluorouracil and its orally active prodrug capecitabine are fluoropyrimidines, belonging to the class of antimetabolites used for treatment of malignancies of breast, head and neck tumours and gastrointestinal tumours.
Mechanisms for coronary vasospasm
Endothelial cell damage with cytolysis and denudation
Increased endothelin-1 bioactivity leading to vasoconstriction
When high dose infusions are given, coronary vasospasm with angina, arrhythmia or even sudden death can occur in up to 5% of patients. Vascular toxicity occurs generally within 72 hours of the...
Source: Cardiophile MD - November 13, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
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
