Cardiophile Common

What is tmt test for heart ?

Johnson Francis — Tue, 12 Jun 2012 02:10:19 +0000

TMT is short for treadmill test. Treadmill is a device used for exercise testing. The subject walks on a motorized belt, the speed and gradient of which can be adjusted. There are various protocols for treadmill testing. One popular protocol is known as the Bruce protocol in which the initial slope (gradient) of the treadmill is 10 percent and the gradient increases in steps of 2 percent in each three minute stage. The initial speed is 1.7 miles per hour. It increases to 2.5 miles per hour in the second stage. So on it goes up to stage seven or as much as the subject can tolerate. Now a days the test is computerized so that the speed and gradient of the treadmill is controlled by a computer console which also monitors the ECGElectrocardiogram of the subject and displays it. The computerized console also measures the various ECGElectrocardiogram parameters and displays alerts if necessary. The blood pressure is measured and entered in the console by the operator. The test is conducted in the medical setting by a trained technician with resuscitatory equipment at hand in case of any untoward events.Similar Posts:

What happens to blood pressure when the heart contracts?

Johnson Francis — Tue, 12 Jun 2012 02:03:07 +0000

When the heart contracts, blood is pushed into the blood vessels through the aorta from the left ventricle. This increases the pressure in the blood vessels. The pressure in the blood vessels when the heart contracts is known as the systolic blood pressure. The blood pressure in the vessels fall when the heart relaxes and the pressure in the blood vessels when the heart relaxes is known as the diastolic blood pressure. Systole is the technical term for contraction of the heart and diastole the term for relaxation of the heart.Similar Posts:

Ballon mitral valvotomy – the modern treatment for mitral stenosis

Johnson Francis — Mon, 11 Jun 2012 15:41:05 +0000

Long back, mitral stenosisNarrowing (of a valve or blood vessel) (narrowing of the valve between the left atrium and left ventricle) used to be treated by a surgery known as closed mitral valvotomyOpening up of the narrowed valve in which the surgeon used to open the chest and introduce a mechanical device to enlarge the narrowed valve through the tip of the left ventricle. Currently this procedure has become obsolete and almost extinct with the development of balloon mitral valvotomyOpening up of the narrowed valve. In this procedure, balloon at the tip a long tube (balloon catheter) is used to enlarge the narrowed valve. The balloon catheter for this procedure is introduced through the femoral vein in the groin under local anaesthesia. It moves up the inferior vena cava into the right atrium. Entry from right atrium to left atrium is preformed using a needle and dilated introduced through the femoral vein prior to introduction of the balloon tipped catheter. From the left atrium, the balloon is introduced into the left ventricle, across the narrowed mitral valve. Once it is positioned across the mitral valve, the balloon is inflated using dilute radiocontrast to achieve enlargement of the narrowed mitral valve. The whole procedure is guided by X-ray fluroscopy and is done in a cardiac catheterization laboratory, by trained personnel.Similar Posts:

Dyeless angiography

Johnson Francis — Mon, 11 Jun 2012 15:32:28 +0000

Angiography or imaging of blood vessels usually require injection of a radiocontrast (dye) into the blood vessels and imaging them with X-ray technology. Dyeless angiography is possible with magnetic resonance imaging where the signals from the moving hydrogen particles in blood give the image. This is known as magnetic resonance angiography. This avoids the risk of radiocontrast dyes which could produce adverse effects like allergic reaction, kidney dysfunction, transient suppression of cardiac function producing fall in blood pressure etc.

Another form of angiography which does not use radiocontrast material is carbon dioxide angiography in which gaseous carbon dioxide is injected in the blood vessel, typically into the renal artery for renal angiography. This produces a negative contrast compared to usual radiocontrasts. Carbon dioxide gets rapidly absorbed into the blood and there is no adverse effect, though the visualisation is not as good as other radiocontrast agents.Similar Posts:

Can psychological stress cause cardiac arrhythmia?

Johnson Francis — Mon, 11 Jun 2012 06:47:20 +0000

Many of the cardiac arrhythmias can be worsened with psychological stress. During psychological stress, the stress related hormones (e.g. adrenaline, a catecholamine) is released into the blood stream. This is due to activation of the sympathetic nervous system. Catecholamines can enhance the irritability of the heart and increase the chance of abnormal heart rhythm. There are certain heart rhythm disorders which can be specifically worsened by stress. These include certain varieties of long QT syndromes and a rare condition known as catecholaminergic polymorphic ventricular tachycardiafast rhythm of the heart. In these conditions, sudden psychological stress can even be life threatening. Stress can also worsen myocardial oxygen demand and worsen blood supply to regions of heart already suffering ischemia (reduced blood supply) and cause cardiac arrhythmiaabnormal heart rhythmIrregular rhythm of the heart.Similar Posts:

How does a defibrillator restart the heart?

Johnson Francis — Sat, 09 Jun 2012 14:55:47 +0000

Defibrillator is a device which can deliver a controlled high voltage shock which lasts for a very short period. A heart which has stopped could be in either ventricular fibrillation or ventricular asystole. Rarely it could also be pulseless electrical activity during a cardiac arrest. A defibrillator is useful only in ventricular fibrillation. In ventricular fibrillation heart stops pumping because of a very rapid and disorganized electrical activity of the heart muscle. What a defibrillator does is to abolish this disorganized electrical activity (ventricular fibrillation) by giving a high voltage shock. When the abnormal activity is abolished, the natural pacemaker of the heart known as the sinus node has an opportunity to take control of the heart rhythm. If the sinus node is able to take over the control of the heart rhythm, the heart starts beating normal. This is possible only if too much time has not elapsed between the cardiac arrest and initiation of cardiopulmonary resuscitation.Similar Posts:

Is heart attack always fatal?

Johnson Francis — Mon, 04 Jun 2012 14:28:54 +0000

Not at all. Only some unfortunate victims of heart attack die suddenly. Most of them do survive to reach the hospital and many of them lead normal lives after discharge from the hospital. It all depends on how severe the attack is and how promptly you get medical attention. Many sudden cardiac arrests due to heart attacks can be revived if cardiopulmonary resuscitation (CPRCardiopulmonary resuscitation) is initiated promptly. An automatic external defibrillator can be helpful in this situation to shock the heart rhythm back to normal. All heart attacks need not cause a cardiac arrest, which is abrupt cessation of the pumping activity of the heart, usually due to an abnormal heart rhythm.Similar Posts:

Can supraventricular ectopics appear like ventricular ectopics?

Johnson Francis — Mon, 04 Jun 2012 14:22:40 +0000

Supra ventricular ectopics are premature beats originating from from a focus above the ventriclesLower chambers of the heart other than the sinus node. Usually they have a narrow QRS complex with a duration less than 120 milliseconds. But when the conduction down to the ventriclesLower chambers of the heart are abnormal as in a pre-existing bundle branch block or a transient conduction block induced by prematurity, the QRS complexes can be wide and mimic a ventricular ectopic beat. But a preceding P wave if present may indicate the supraventricular origin. It is also possible to have a ventricular ectopic soon after a sinus P wave which appears in a similar way.Similar Posts:

What is myocardial infarction?

Johnson Francis — Mon, 04 Jun 2012 14:15:43 +0000

Myocardial infarction is the medical name for heart attack. It is damage to a region of the heart muscle due to abrupt cessation of blood supply to that region. It could be due to sudden occlusion of a branch of a coronary artery supplying that region or abrupt spasm (contraction of the smooth muscle of the blood vessel wall) which persists long enough to produce damage to the heart muscle. It can also be due to lodgment of small clot arising elsewhere in a branch of the coronary artery. Myocardial infarction is a potentially life threatening condition unless prompt medical attention is obtained. It usually presents as severe chest pain, though occasionally it can be painless and present with atypical symptoms like breathlessness, sweating or fatigue.Similar Posts:

What is cryoablation?

Johnson Francis — Tue, 29 May 2012 03:08:09 +0000

Cryoablation is a method used to treat heart rhythm disorders by freezing the abnormal region using a cryoprobe. While radiofrequency ablation removes an abnormal focus or pathway by heating up the tissue, cryoablation does the same by cooling the tissue to sub-zero temperature. Currently the cryoprobe is much more expensive than the radiofrequency ablation system and is not as widely available. The advantage of cryoprobe is the reversibility while treating foci near to critical cardiac structure. Initial cooling to some extends blocks the conduction and helps to assess whether the treatment will be effective and whether any adjacent critical structure will be damaged. If any collateral damage is detected, all you have to do is to rewarm to undo the damage done. If no collateral damage is detected, further cooling produces a permanent treatment effect. Though the chance for collateral damage is less, the efficacy also may be a little lower than radiofrequency catheter ablation because of the slightly higher chance or recurrence.Similar Posts: