http://WWW.HEARTDIABETESCARE.COM
SAMIKSHAHEARTCARE 57698d5b9ec66b0b6cfb5b6b False 575 1
OK
background image not found
Found Update results for
'atrioventricular nodal reentrant tachycardia'
9
POPULAR CARDIOLOGISTS IN SILK BOARD Atrial tachycardia with block Atrial tachycardia with block (paroxysmal atrial tachycardia (PAT) with block) is also an autonomous (automatic, ectopic) atrial tachycardia but its P waves are usually smaller (often discernible only in lead V1) and faster. As a result of this high rate, AV block—mostly 2:1, but often variable—is usually present prior to any exposure to drugs or vagal manoeuvres ). inthe past this was one of the classic manifestations of digoxin toxicity. It can be difficult to distinguish from other atrial rhythms such as AF, flutter and even sinus rhythm ..
POPULAR CARDIOLOGISTS IN H S R LAYOUT Ventricular tachycardia Ventricular tachycardia is defined as three or more ventricular ectopic beats at a rate over 100/minute. It is said to be sustained if it lasts more than 30 seconds. Most broad-complex tachycardias are ventricular (rather than supraventricular with aberrant conduction). The diagnosis of VT is greatly strengthened if there is a history of myocardial infarction or cardiac failure but, oddly enough, the patient’s haemodynamics are of no help. A number of criteria have evolved over the years to help ascertain the diagnosis of VT over aberrancy. These include: evidence of AV dissociation—P waves can be seen unrelated to the QRS complexes (they are usually visible only at relatively slow VT rates) the presence of supraventricular capture or fusion beats visible retrograde conduction with 2:1 block (P waves visible following every second complex) the presence of monophasic R, qR or QR patterns in V1, provided a septal infarction has not modified a RBBB a taller left rabbit ear in RR' or qRR' complexes in V1 n QS complexes in V1 with a slow S descent and sharp upstroke—the opposite of LBBB—or a broad small primary R wave in rS morphology (the Rosenbaum pattern) RAD in the frontal plane with LBBB-like QRS complexes
Indications for Hemodynamic Monitoring in Patients with STEMI Management of complicated acute myocardial infarction Hypovolemia versus cardiogenic shock Ventricular septal rupture versus acute mitral regurgitation Severe left ventricular failure Right ventricular failure Refractory ventricular tachycadia Differentiating severe pulmonary disease from left ventricular failure Assessment of cardiac tamponade Assessment of therapy in selected individuals Afterload reduction in patients with severe left ventricular failure Inotropic agent therapy Beta-blocker therapy Temporary pacing (ventricular versus atrioventricular) Intraaortic balloon counterpulsation Mechanical ventilation
THE HYPERDYNAMIC STATE. MI with hyperdynamic state—that is, elevation of sinus rate, arterial pressure, and cardiac index, occurring singly or together in the presence of a normal or low left ventricular filling pressure—and if other causes of tachycardia such as fever, infection, and pericarditis can be excluded, treatment with beta blockers is indicated. Presumably, the increased heart rate and blood pressure are the result of inappropriate activation of the sympathetic nervous system, possibly secondary to augmented release of catecholamines, pain and anxiety, or some combination of these.
HEART SPEACIALIST IN BANGALORE HYPERTENTION By definition, sinus tachycardia is a heart rate ≥ 100/minute and sinus bradycardia is a heart rate ≤ 50/minute.3 To calculate the heart rate from the ECG, the R-R interval in mm can be divided into 1500. For example, an R-R interval of 20 mm gives a rate of 75/minute and an R-R interval of 15 mm gives a rate of 100. Similarly, large 5 mm squares can be divided into 300; thus three squares give a rate of 100/minute. In regular rhythms, any two congruous points of the P-QRS-T sequence can be used to estimate the rate. An ECG ruler has a scale that enables rapid rate measurement and calculation of other intervals. With practice, the rate can be estimated at a glance.
CARDIOLOGIST IN YELAHANKA SECOND DEGREE AV BLICK There are two basic types of second-degree AV block: AV nodal Möbitz type I (Wenckebach) heart block, and the more distal and more sinister Möbitz type II heart block. Möbitz type I heart block is much more common. In Möbitz type I block the PR interval lengthens progressively with each cardiac cycle, until an atrial wave is not conducted. There is recovery of conduction and the next a wave is conducted with a shorter interval and the cycle begins again. The QRS complex is narrow (Fig 3.10) (unless associated with pre-existing BBB). The increment is largest between the first and second conducted P wave, and the PR interval continues to increase by less and less until a P wave is dropped. Möbitz type II heart block is almost always associated with a BBB (Fig 3.11), since its origin is intraventricular (below the AV node), and it tends to lapse suddenly into extreme bradycardia or asystole. It tends to be over-diagnosed, especially in the setting of 2:1 AV block (Fig 3.12). There is no lengthening of the PR interval before an atrial wave is not conducted. At times, atropine or exercise can demonstrate the site of the block, by increasing the block from 2:1 to a higher grade when the underlying mechanism is Möbitz II. Conversely, Wenckebach conduction may improve to 3:2 or better. For a distinction to be made between Möbitz type I and Möbitz type II, at least two consecutively conducted P waves have to be evaluated. This is impossible in 2:1 conduction (block) and can only be reported as 2:1 AV block (Fig 3.12). Yet this is very commonly reported as
THE BEST CARDIOLOGISTS IN YELAHANKA Second-degree AV block There are two basic types of second-degree AV block: AV nodal Möbitz type I heart block, and the more distal and more sinister Möbitz type II heart block. Möbitz type I heart block is much more common. In Möbitz type I block the PR interval lengthens progressively with each cardiac cycle, until an atrial wave is not conducted. There is recovery of conduction and the next a wave is conducted with a shorter interval and the cycle begins again. The QRS complex is narrow (unless associated with pre-existing BBB). The increment is largest between the first and second conducted P wave, and the PR interval continues to increase by less and less until a P wave is dropped. Möbitz type II heart block is almost always associated with a BBB , since its origin is intraventricular (below the AV node), and it tends to lapse suddenly into extreme bradycardia or asystole. It tends to be over-diagnosed, especially in the setting of 2:1 AV block . There is no lengthening of the PR interval before an atrial wave is not conducted. At times, atropine or exercise can demonstrate the site of the block, by increasing the block from 2:1 to a higher grade when the underlying mechanism is Möbitz II. Conversely, Wenckebach conduction may improve to 3:2 or better. For a distinction to be made between Möbitz type I and Möbitz type II, at least two consecutively conducted P waves have to be evaluated. This is impossible in 2:1 conduction (block) and can only be reported as 2:1 AV block (Fig 3.12). Yet this is very commonly reported as Möbitz type
THE CARDIOLOGISTS IN HSR LAYOUT Atrial fibrillation Atrial fibrillation is the most common sustained arrhythmia. The atrial activity consists of chaotic, small fibrillatory f waves at 400–700/minute. The ventricular response is usually 130–160/minute and is irregular. The ventricular response rate is slower if the patient has been treated with anti-arrhythmic drugs or if there is intrinsic AV nodal disease. When the response rate is slow, the AF is often reported as ‘controlled’ . very rapid ventricular response—more than 200/minute—may be seen in the presence of a bypass tract, like the bundle of Kent in WPW syndrome (Fig 3.24) or James fibres in LGL syndrome . The AF itself should never be reported as ‘fast’ because it always
CARDIOLOGISTS IN BANGALORE Arrhythmias during pregnancy Women with congenital heart disease are at increased risk of supraventricular arrhythmias during pregnancy. Anti-arrhythmic drug treatment may be necessary for recurrent episodes. Digoxin may be useful for the control of heart rate but is often not effective. Beta-blockers and verapamil have been used for these patients and appear to be free of teratogenic effects.27 Amiodarone is a more effective anti-arrhythmic drug than these but should be reserved for intractable cases and used at the lowest useful dose.28 Sustained tachycardias (atrial flutter is the most common) are not well tolerated in pregnancy and DC cardioversion should be performed without delay for these patients.
1
false