What is the difference between pulsed wave and continuous wave doppler?
In pulsed wave Doppler, same piezoelectric crystal is used to transmit and receive the echo from the sample volume. Hence the signals are sent out in pulses and the intervals between the pulses are used to receive the echoes. In continuous wave Doppler, one piezoelectric crystal transmits continuously and another one receives continuously. As the transmission and reception are continuous, it is not possible to find out the depth from which the return signals are received. At the same time continuous wave Doppler can analyze higher velocities while pulsed wave Doppler can analyze only lower velocities.
In case of pulsed Do...
Source: Cardiophile MD - October 20, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is ambulatory blood pressure monitoring? Cardiology Basics
Usually blood pressure is measured with two or three recordings in the clinic or at the bedside. Blood pressure is known to fluctuate throughout the day depending on activities and stress. So, a recording from the clinic may not reflect the average blood pressure during a 24 hour period. Studies have shown that average daily blood pressure is more important than single recordings in deciding the target organ damage due to hypertension.
In ambulatory blood pressure monitoring, a blood pressure cuff applied to the arm is automatically inflated and deflated periodically by a battery driven device attached to the belt. Record...
Source: Cardiophile MD - October 19, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is high altitude pulmonary edema (HAPE)? Cardiology Basics
High altitude pulmonary edema is pulmonary edema which occurs on rapid ascent to high altitudes. It is a potentially life threatening condition and is a severe form of mountain sickness. Severe breathlessness with fall of oxygen level in the blood occurs in this condition. Cyanosis may be noted. The best way to prevent it is to ascend gradually, taking a few days to climb to 3000 meters. After that climb only very slowly, only about 300 to 500 meters a day. The risk is more if your usual residence is near sea level so that you are not acclimatized to high altitude at all. Previous episode increases your risk of a recurren...
Source: Cardiophile MD - October 19, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
What is TAPVC? Cardiology Basics
TAPVC stands for total anomalous pulmonary venous connection. It is also known as TAPVD or total anomalous pulmonary venous drainage. Normally, pulmonary veins join the left atrium. When it drains to the right atrium through one of the blood vessels leading to the right atrium, it is known as TAPVC. If only some of the four pulmonary veins join the right side of the heart, then it is called PAPVC or partial anomalous pulmonary venous connection.
When all the pulmonary veins join the right side of the heart instead of the left side, an atrial septal defect (ASD) is needed to maintain life. Otherwise body will not get any o...
Source: Cardiophile MD - October 19, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Pulmonary stenosis – Cardiology Basics
Pulmonary stenosis – Cardiology Basics
Pulmonary stenosis is most often congenital, though occasionally it can occur in carcinoid syndrome and related disorders. Dysplastic pulmonary valve occurs in Noonan’s syndrome. Pulmonary stenosis increases the workload of the right ventricle, which gets hypertrophied in an attempt to overcome the obstruction. Hypertrophied right ventricle becomes less compliant, increasing its filling pressure.
Decrease in right ventricular compliance increases right atrial pressure. This will be more when the right ventricle fails ultimately. Forceful right atrial contraction produces a...
Source: Cardiophile MD - October 18, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
How is pulmonary embolism treated? Cardiology Basics
Pulmonary embolism is obstruction of pulmonary arteries due to emboli migrating from other parts of the body. It is a potentially life threatening condition if a major branch or multiple branches are obstructed. More emboli can travel to the lungs from the original source and hence pulmonary embolism may worsen later even if the initial episode involves only a small portion of the lungs. So, it is important to treat pulmonary embolism even if it is mild. Treatment options will depend on the severity of the situation.
Initial treatment will be with parenteral anticoagulants like heparin or low molecular weight heparin. Aft...
Source: Cardiophile MD - October 18, 2022 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
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
