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What are the functions of pericardium ?

What are the functions of pericardium ?  • The pericardium protects and lubricates the heart.  • It contributes to the diastolic coupling of the left and right ventricles - an effect that is important in cardiac tamponade and constrictive pericarditis.  W. Dressier (1890-1969), US physician educated in Vienna. He worked at the I Manimoides Hospital, Brooklyn, New York.

What do you know about postcardiotomy syndrome ?

What do you know about postcardiotomy syndrome ?  It occurs in about 5% of patients who have cardiac surgery, with symptoms of pericarditis from three weeks to six months after surgery. It is initially treated with NSAIDs and systemic steroids in refractory cases.  Pericardiectomy is rarely required. It is said to result from an autoimmune response and is most likely to be related to surgical trauma and irritation of blood products in the mediastinum and pericardium.

What is Dressler's syndrome ?

What is Dressler's syndrome ?  Dressler's syndrome is characterized by persistent pyrexia, pericarditis and pleurisy.  It was first described in 1956 when Dressier recognized that post-myocardial infarction chest pain is not caused by coronary artery insufficiency.  It usually occurs 2-3 weeks after myocardial infarction and is considered to be of autoimmune aetiology; it responds to NSAIDs.

What do you know about the transient constrictive phase of acute pericarditis ?

What do you know about the transient constrictive phase of acute pericarditis ?  About 10% of the patients with acute pericarditis have a transient constrictive phase which may last 2-3 months before it gradually resolves, either spontaneously or with treatment with anti-inflammatory drugs. These patients usually have a mod-erate amount of pericardial effusion and, as the effusion resolves, the pericardium remains thickened, inflamed and non-compliant resulting in constrictive haemo-dynamics. Clinical features include shortness of breath, raised jugular venous pressure, peripheral oedema and ascites. Constrictive haemodynamics can be documented by Doppler echocardiography and resolution of constrictive physiology can be serially followed by this technique.

What is the treatment for acute pericarditis ?

What is the treatment for acute pericarditis ?  • Pain relief (codeine) and anti-inflammatory agents (non-steroidal anti-inflammatory drugs (NSAIDs) such as indometacin).  • Steroids should be considered only when the pain does not respond to a com-bination of NSAIDs.  • Treatment of the underlying cause.  • Colchicine has been used to treat recurrent pain of pericarditis, and rarely peri-cardiectomy may be required for pain even in the setting of no haemodynamic impairment.

What are the characteristic features of a pericardial friction rub ?

What are the characteristic features of a pericardial friction rub ?  It typically consists of three components: a presystolic rub (during atrial contrac-tion), a ventricular systolic rub (which is almost always present and usually the loudest component) and a diastolic rub which follows the second heart sound (during rapid ventricular filling).

Mention some indications for implantable cardiac defibrillators.

Mention some indications for implantable cardiac defibrillators.  • Cardiac arrest resulting from ventricular tachyarrhythmia not due to a reversible or transient cause (remember: patients who have cardiac arrest unrelated to acute myocardial infarction have approximately a 35% chance of recurrent ventricular arrhythmias within the first year).  • Spontaneous sustained ventricular tachycardia.  • Syncope of undetermined origin with inducible sustained ventricular tachycardia on electrophysiological study and when drug therapy is not effective or tolerated.  • Non-sustained ventricular tachycardia with coronary artery disease and inducible ventricular tachycardia on electrophysiological study that is not suppressible by a class I antiarrhythmic drug.

What is the pacemaker syndrome ?

What is the pacemaker syndrome ?  It is seen in individuals with a single-chamber pacemaker who experience symptoms of low cardiac output (dizziness, etc.) when erect; it is attributed to the lack of atrial kick. Pacemaker syndrome is caused by haemodynamic changes as a consequence of inappropriate use of ventricular pacing: it occurs when ventricular pacing is uncoupled from atrial contraction.  It is most common when the VVI mode is used in patients with sinus rhythm but can occur in any pacing mode when atrioventricular synchrony is lost. Levels of atrial natriuretic factor are high in pacemaker syndrome.  If pacemaker syndrome occurs in a patient with a VV1 pacemaker the only definitive treatment is to convert to a dual-chamber pacemaker. If the patient has occasional bradycardia then often symptoms may be ameliorated by programming the pacemaker to a lower limit and programming with hysteresis 'on'.  This allows the patient to stay in normal sinus rhythm for longer

What are the complications of pacemakers ?

What are the complications of pacemakers ?  • Erosion through the skin due to mechanical factors.  • Infection.  • Lead displacement or lead fracture (the most common site of pacing lead fracture is between the first rib and the clavicle).  • Pacemaker malfunction.  • Electromagnetic interference.  • Pain/ecchymoses at the site of insertion.  • Pneumothorax.

Mention some expanded uses of cardiac pacing.

Mention some expanded uses of cardiac pacing.  • Dual chamber pacing has been used to optimize cardiac output and minimize the outflow tract gradient in patients with hypertrophic obstructive cardiomyopathy.  • Dual chamber pacing is currently being investigated in dilated cardiomyopathy with heart failure and intraventricular conduction delay to optimize AV delay and improve cardiac output.  • Dual-site atrial pacing to prevent atrial fibrillation is being evaluated.

What do you know about permanent pacemakers ?

What do you know about permanent pacemakers ?  * They are connected to the heart by one or two electrodes and are powered by long-lasting (5-10 years) solid-state lithium batteries. Most pacemakers are designed to pace and sense the ventricles - called the VVI pacemakers because they pace the ventricle (V), sense the ventricle (V) and are inhibited (I) by the ventricular signal. They are inserted under local anaesthesia and fluoroscopic guidance, subcutaneously under the pectoral muscles. • In symptomatic sinus tachycardia, an atrial pacemaker may sometimes be implanted (AAI). • In sick sinus syndrome, a dual-chamber pacemaker DDD (because it paces two or dual chambers, senses both (D) and reacts in two (D) ways, i.e. pacing in the same chamber is inhibited by spontaneous atrial and ventricular signals, and ventricular pacing is triggered by spontaneous atrial events) is implanted. • Rate-responsive pacemakers measure activity, respiration, biochemical and electrical indicators

What are the indications for a permanent pacemaker ?

What are the indications for a permanent pacemaker ?   • Symptomatic bradyarrhythmias (heart rate <40 beats/min or documented periods of asystole >30 seconds when awake). Symptoms include syncope, pre-syncope, confusion, seizures, or congestive heart failure and they must be clearly related to the bradycardia.   • Asymptomatic Mobitz type I1 atrioventricular block (N Engl d Med 1998; 338: 1147-8).   • Complete heart block.

How would you treat a patient with constrictive pericarditis ?

How would you treat a patient with constrictive pericarditis ?  • Surgery is the only satisfactory treatment: Complete surgical resection of the pericardium (myocardial inflammation or fibrosis may delay symptomatic response). Patients with tuberculous pericarditis should be pre-treated with antituberculosis therapy; if the diagnosis is confirmed after pericardial resection, full anti-tuberculous therapy should be continued for 6-12 months after resection. C.S. Beck (1894-1971), surgeon, Peter Bent Brigham Hospital in Boston. W. Broadbent(1868-1951), English physician who qualified from St Mary's Hospital Medical School, London. He described the Broadbent sign in constrictive pericarditis, which is an indrawing of the 11th and 12th left ribs with a narrowing and retraction of the intercostal space posteriorly; this occurs as a result of pericardial adhesions to the diaphragm.

How would you investigate a patient with constrictive pericarditis ?

How would you investigate a patient with constrictive pericarditis ?  • Chest radiograph typically shows normal heart size and pericardial calcification (note: the combination of pulsus paradoxus, pericardial knock and pericardial calcification favours the diagnosis of constrictive pericarditis). • ECG shows low voltage complexes, non-specific T wave flattening or atrial fibrillation. • Echocardiogram shows myocardial thickness is normal and may reveal thickened pericardium; normal ventricular dimensions with enlarged atria and good systolic and poor diastolic dysfunction.  Doppler shows increased right ventricular systolic and decreased left ventricular systolic velocity with inspiration, expiratory aug-mentation of hepatic vein diastolic flow reversal. • CT scan or MRI: shows normal myocardial thickness usually, and pericardial thickening and calcification. • Cardiac catheterization typically shows identical left and right ventricular filling pressures and pulmonary artery

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