What are the precautions for undergoing a treadmill test (TMT)? Cardiology Basics
Treadmill exercise test is often taken as a fitness test during routine medical check-up. TMT is also done for evaluation of a case of suspected coronary artery disease and as part of post myocardial infarction evaluation. TMT in children is often for the evaluation of arrhythmic disorders. But this is not a test meant for everyone coming for a health check-up. A preliminary assessment of the fitness of an individual to undergo a treadmill test (TMT) is desirable.
This will include a short check on whether the person has any medical conditions which could increase the risk of the test. Moreover, it is difficult for person...
Source: Cardiophile MD - October 18, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is carbon dioxide angiography? Cardiology Basics
Carbon dioxide angiography is done using carbon dioxide injection into the blood vessel. Usually iodine containing radiocontrast dyes are injected into the blood vessels and continuous X-ray imaging done, to obtain angiograms.
Contrast material is needed to visualize the blood vessel separately from the other body tissue. But usual iodinated radiocontrast dyes have a potential risk of causing acute kidney injury. This is more so in those with already impaired renal function. It is in this situation that carbon dioxide angiography is usually considered.
Usual angiograms appear dark while carbon dioxide angiogram look...
Source: Cardiophile MD - October 17, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is complete heart block? Cardiology Basics
When natural pacemaker impulses from the sinoatrial node fails to reach the ventricles and activate them, it is known as complete heart block. The block could be at the level of the atrioventricular (AV) node or below that.
Sinus node is a subepicardial structure located in the upper part of right atrium near the orifice of the superior vena cava. Signals from sinus node travel to the AV node through three internodal pathways. They are Wenckebach, Thorel and Bachmann bundles. Bachmann bundle gives a branch to the left atrium also.
AV node is located near the atrioventricular junction in the lower part of right atrium. It ...
Source: Cardiophile MD - October 17, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What happens to blood pressure and heart rate with exercise? Cardiology Basics
In a normal person, the heart rate and blood pressure progressively increase with progressive exercise. The rise in blood pressure is mostly in the systolic pressure. Hence the pulse pressure is high during maximal exercise.
The maximum predicted heart rate is 220 – age of the person (Astrand’s formula) [1]. The increase in heart rate is needed in order to increase the cardiac output, to meet the demands of the exercising muscles. Systolic blood pressure and heart rate rise mainly due to the enhanced sympathetic activity. There is also a withdrawal of the activity of the parasympathetic nervous system.
Increased cardi...
Source: Cardiophile MD - October 16, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is DM Cardiology? Cardiology Basics
DM Cardiology (Doctor of Medicine – Cardiology) is a three year full-time course conducted at various medical colleges and institutes of national importance in India. Cardiology is the branch of medicine dealing with cardiovascular disorders.
Selection to the various medical colleges is by the National Eligibility Cum Entrance Test – Super Specialty (NEET-SS), while that to institutes of national importance is by Institute of National Importance Combined Entrance Test (INI CET).
NEET-SS is conducted by the National Board Of Examinations In Medical Sciences, New Delhi. INI CET is conducted by All India Institute of Med...
Source: Cardiophile MD - October 16, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
How does stress cause heart disease? Cardiology Basics
Stress and heart disease have various aspects. Stress can lead to increase in risk factors for cardiovascular disease as well as precipitate symptoms in a hitherto silent cardiovascular disease. There is also a condition known as stress cardiomyopathy or broken heart syndrome, typically precipitated by an acute stressful event like loss of spouse in an elderly female.
Most older persons have build-up of atherosclerotic plaques in the coronary arteries. When there is a sudden severe stress, heart rate and blood pressure can shoot up due to sympathetic overactivity. There is also the release of stress hormones like adrenali...
Source: Cardiophile MD - October 16, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
How can exercise prevent cardiovascular disease? Cardiology Basics
Dr. Paul Dudley White, the famous physician who has taught many a luminary in the field of cardiology once wrote that heart disease before eighty is our fault and not God’s will or nature’s will.
This means that he recognized long back, the role of life-style modification in preventing heart disease. Exercise in a regular pattern is one of the important life style modifications which everyone can adopt to prevent or delay cardiovascular disease. Exercise helps in various ways for prevention of cardiovascular disease. In those with established cardiovascular disease, graded exercise programs can promote the formation o...
Source: Cardiophile MD - October 15, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is colour Doppler echocardiography? Cardiology Basics
Usual colour Doppler echocardiogram is superimposition of colour Doppler images on a two dimensional echocardiogram. Colour M-Mode is superimposition of colour Doppler images on an M-Mode echocardiogram. The principle of Doppler is that the frequency of sound wave coming from an object which is moving towards the ultrasound probe increases while that from an object moving away from the probe decreases. It is similar to the difference in the sound of a train whistle, which is different when the train is moving towards you than when it is moving away from you. In Doppler echocardiography, the target is moving red blood cell...
Source: Cardiophile MD - October 14, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is thrombolytic therapy for myocardial infarction? Cardiology Basics
Thrombolytic therapy used to be an important mode of early treatment of acute myocardial infarction. Though it has been largely superseded by primary angioplasty, thrombolytic therapy may still be useful in certain situations. It is still an important form of treatment in resource limited locations.
Myocardial infarction is usually due to sudden occlusion of a coronary artery by thrombus formation on a pre-existing partial obstruction by an atherosclerotic plaque. Plaque rupture with local thrombus formation is the usual mechanism. Dissolving the thrombus soon after the occurrence of a myocardial infarction can salv...
Source: Cardiophile MD - October 14, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is a perimembranous VSD? Cardiology Basics
Perimembranous VSD is the commonest type of ventricular septal defect. When there is a ventricular septal defect, blood shunts from the left ventricle to the right ventricle as the pressure in the left ventricle is higher. This leads to increased pulmonary blood flow. VSD usually occurs as a congenital defect, though it can rarely occur in the adult after a myocardial infarction due to rupture of the ventricular septum. If the VSD is large, high pulmonary blood flow increases the amount of blood returning to the left atrium and left ventricle through the pulmonary veins. This volume overloading of the left ventricle can l...
Source: Cardiophile MD - October 14, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Is first degree heart block dangerous? Cardiology Basics
PR interval is measured from the onset of P wave to the onset of QRS complex. It includes the P wave and the PR segment. Normal PR interval is from 120 to 200 ms. If it is prolonged, it is called as first degree atrioventricular (AV) block.
PR interval is the time taken for activation of the atria and conduction of the impulses down to the ventricles and initiate activation of the ventricles. This includes the physiological delay in conduction at the AV node. The delay allows complete emptying of the atria before the ventricles start contracting. The atrial help to ventricular filling acts like an atrial booster at the en...
Source: Cardiophile MD - October 14, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is myocardial stunning and hibernation? Cardiology Basics
Just as you can get stunned for some time if hit on the head, part of the myocardium can also stop functioning following transient coronary obstruction. This usually occurs following a myocardial infarction after which the occluded coronary artery gets opened up spontaneously or by thrombolytic therapy or primary angioplasty.
After a variable period of time, the stunned myocardium usually recovers full function. During the period of stunning, if a large part of myocardium is involved, the person may have features of heart failure due to decreased left ventricular systolic function. Myocardial stunning is the reason for he...
Source: Cardiophile MD - October 13, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What are the dangerous signs on Holter monitoring? Cardiology Basics
Holter monitoring is an ambulatory ECG monitoring, usually with a digital recorder, attached to a belt, typically for 24 to 48 hours. Two or three channels are usually recorded with an appropriate number of patch electrodes attached to the chest. Holter monitoring is usually done when a cardiac arrhythmia as the cause of symptoms is suspected. It can also be done to detect atrial fibrillation as part of post stroke workup.
Dangerous signs to look for on a Holter tracing are life threatening tachy and bradyarrhythmias. Here is a long pause which could cause syncope. This is a long sinus pause in sick sinus syndrome. Sympto...
Source: Cardiophile MD - October 13, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is the difference between CRT-P and CRT-D? Cardiology Basics
In cardiology, CRT stands for cardiac resynchronization therapy. CRT is used in heart failure with reduced ejection fraction. According to the Universal Definition and Classification of Heart Failure, heart failure with reduced ejection fraction has left ventricular ejection fraction of 40% or less. CRT is a type of pacemaker in which three chambers of the heart are paced, right atrium, right ventricle and left ventricle.
This picture illustrates what reduced ejection fraction means. Ejection fraction is the fraction of end diastolic volume which is pumped out from the left ventricle during systole. Normal ejection fracti...
Source: Cardiophile MD - October 13, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What are the types of myocardial infarction? Cardiology Basics
World Heart Federation along with major European and North American Heart Societies have brought forth the universal definition of myocardial infarction. It has been revised the fourth time in 2018. In the latest revision myocardial infarction has been classified into 5 types, of which type 4 has three subtypes as well.
Type 1 is the type of myocardial infarction which all of us are familiar with. It occurs due to sudden occlusion of a coronary artery. This leads to chest pain and ECG changes. Myocardial damage can be noted on echocardiography as well as other imaging modalities like cardiac magnetic resonance imaging (CM...
Source: Cardiophile MD - October 13, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
