Heart 4

oelomar's version from 2016-05-16 23:01


Question Answer
What are the causes of aortic stenosis?Congenital (bicuspid, unicuspid valve), calcification (wear and tear), rheumatic disease.
What are the symptoms of aortic stenosis?There are usually no symptoms until aortic stenosis is moderately severe. At this stage, there is the classic triad of exertional dyspnoea, angina, and syncope.
What is the prognosis of aortic stenosis?When symptoms occur, the prognosis is poor – on average, death occurs within 2-3 years if there has been no surgical intervention.
What are the signs of aortic stenosis?The carotid pulse is of small volume and is slow-rising or plateau in nature. An ejection systolic murmur that is usually ‘diamond-shaped’ (crescendo– decrescendo) is also heard. The murmur is best heard in the aortic area. It radiates into the carotid arteries and also the precordium.
What are the causes of aortic regurgitation?Aortic regurgitation can occur in diseases affecting the aortic valve e.g. endocarditis, and diseases affected the aortic root e.g. Marfan’s.
What are the symptoms of aortic regurgitation?Usually only becomes symptomatic late in disease when LV failure develops. Symptoms include dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea, syncope, angina.
What are the signs of aortic regurgitation?Bounding or collapsing pulse, Quincke’s sign (capillary pulsation in nail beds), De Musset’s sign (head nodding with each heartbeat), Corrigan’s sign (carotid pulsations), Duroziez’s sign (a to-and-fro murmur heard when the femoral artery is auscultated with pressure applied distally), Traube’s sign (pistol shot femorals – a sharp bang heard on auscultation over the femoral arteries in time with each heartbeat). The apex beat is displaced laterally and downwards and is forceful in quality. On auscultation, there is a high-pitched early diastolic murmur best heard at the left sternal edge in the fourth intercostal space with the patient leaning forward and the breath held in expiration. Because of the volume overload there is commonly also an ejection systolic flow murmur.
What are the signs and symptoms of aortic sclerosis?Asymptomatic. Signs include an ejection systolic murmur.


Question Answer
How can one manually increase the intensity of right heart sounds?Inspiration.
How can one manually increase the intensity of left heart sounds?Expiration.
How can one manually increase the intensity of the murmurs heard in mitral regurgitation and VSD systolic murmurs?Hand grip (increased system vascular resistance).
What are the most common valves that need replacing?Aortic and mitral.
What are the disadvantages of bioprosthetic valves?These are usually bovine or porcine in origin. The major disadvantage is structural deterioration over time – they tend to degenerate after around 10 years.
What are the advantages of bioprosthetic valves?Long-term anticoagulation is not usually needed. Warfarin may be given for the first 3 months depending on patient factors. Low-dose aspirin is usually given long-term.
What are the advantages of mechanical valves?They have a low failure rate and are more durable than bioprosthetic valves.
What are the disadvantages of mechanical valves?Major disadvantages is the increased risk of thrombosis meaning long-term anticoagulation is needed. Aspirin is normally given unless there is a contraindication.
What is the target INR for a mechanical aortic valve?2.0-3.0.
What is the target INR for a mechanical mitral valve?2.5-3.5.
What antithrombin therapy is indicated for patients with bioprosthetic valves?Aspirin.
What antithrombin therapy is indicated for patients with mechanical valves?Warfarin + aspirin.


Question Answer
What are the causes of atrial fibrillation?The most common causes are hypertension, MI, and heart failure. “Classic” causes include rheumatic heart disease, alcohol intoxication, and thyrotoxicosis. AF can also be a complication CABG or valvular surgery.
What is the atrial rate in atrial fibrillation?300-600 BPM.
What is the main risk associated with atrial fibrillation?Embolic stroke.
What are the signs and symptoms of atrial fibrillation?Asymptomatic in some whilst others attend hospital as an emergency with rapid palpitations, dyspnoea, and/or chest pain. There is an irregularly irregular pulse. The ECG shows fine oscillations of the baseline (so-called f waves) and no clear P waves. The QRS rhythm is rapid and irregular. Untreated, the ventricular rate is usually 120–180 per minute. The clinical classification of atrial fibrillation includes, “acute, paroxysmal, persistent, permanent”.
How is acute atrial fibrillation (<48h) managed?If patient is in a haemodynamically unstable state attempt emergency electrical cardioversion. Otherwise, heparinise patient then cardiovert. Cardioversion can be done electrically (DC cardioversion) or pharmacologically (amiodarone if structural heart disease, flecainide in those without structural heart disease).
Following electrical cardioversion in patients with atrial fibrillation, is further anticoagulation necessary?It is unnecessary if AF is confirmed to as being less than 48 hours duration. If the 48h period has elapsed, cardioversion without anticoagulation is ok if transoesophageal echo shows no thrombus.
To minimise the risk of thromboembolism associated with cardioversion in AF patients, what is done?Patients are fully anticoagulated (INR 2.0–3.0) with warfarin for 3 weeks before cardioversion and at least 4 weeks after the procedure.


Question Answer
What is paroxysmal atrial fibrillation?PAF is defined as at least two separate episodes of AF that terminate spontaneously in less than 7 days, usually within 24 hours. These episodes of AF last greater than 30 seconds and are not related to a reversible cause.
How is paroxysmal AF managed?A rhythm control approach is preferred. A “pill in the pocket” approach may be tried. Otherwise first choice is a beta blocker with sotalol & finally amiodarone for resistant cases. Amiodarone should be first line therapy after beta blocker fails for those with left ventricular failure.
Which two strategies can be used in the long-term management of “persistent” AF?“Rate control” (AV nodal slowing agents plus warfarin) and “rhythm control” (antiarrhythmic drugs plus DC cardioversion plus warfarin).
How is “rhythm control” achieved in patients with AF?Class Ic agents (flecainide) or sotalol are employed in patients with no significant heart disease. Class III agents (amiodarone) are preferred in patients with significant structural heart disease.
How is “rate control” achieved in patients with AF?Rate control is usually achieved by a combination of digoxin, beta-blockers or calcium channel blockers (verapamil or diltiazem) - note that beta-blockers are preferred to digoxin. Digoxin monotherapy may be sufficient for elderly non-ambulant patients. In younger patients beta-blockers or calcium-channel blockers are a good first choice. Target a resting heart rate of less than 90 bpm (110 bpm for those with recent-onset AF).
What factors favour a “rate control” strategy for the long-term management of AF?Older than 65 years, history of IHD.
What factors favour a “rhythm control” strategy for the long-term management of AF?Younger than 65 years, symptomatic, first presentation, CHF.


Question Answer
What is the CHA2DS2-VASc score?A clinical prediction rule which is used to determine the need for anticoagulation in AF patients.
How is the CHA2DS2-VASc score interpreted?0= no treatment required; 1= warfarin or aspirin may be used depending on patient preference and the presence or absence of the additional less validated risk factors; 2= start treatment.
What variables are measured in the CHA2DS2-VASc score?CHF (1), Hypertension (or treated hypertension)(1), Age>75 years (2), Age between 65 and 74 years (1), Diabetes Mellitus (1), Past Stroke/TIA/Thromboembolism (2), Vascular disease (previous MI, peripheral arterial disease, or aortic plaque) (1), Female (1).
What is atrial flutter?An abnormal heart rhythm that occurs in the atria. The atria beat too fast, resulting in them beating out of sync with the ventricles. It falls into the category of supra-ventricular tachycardias. It frequently degenerates into atrial fibrillation.
What is the difference between atrial flutter and atrial fibrillation?AF= random with different rates; chaotic, irregular. Flutter= coordinated atrial contraction at a very fast rate 250-350/min; classically 2:1 conduction – for each 2 atrial contractions is 1 ventricular contraction.
How is atrial flutter managed?Treatment of a symptomatic acute attack is electrical cardioversion. Patients who have been in atrial flutter for more than 1-2 days should be treated in the same manner as patients with AF and anticoagulated for 3 weeks prior to cardioversion.
How is recurrent atrial flutter managed?The treatment of choice is catheter ablation (which permanently interrupts re-entry by creating a line of conduction block within the isthmus between the IVC and the tricuspid valve ring).
What are the symptoms of atrial ectopic beats?These often cause no symptoms although they may be sensed as an irregularity or heaviness of the heartbeat.
How may atrial ectopic beats appear on ECG?Early and abnormal P waves, and are usually, but not always, followed by normal QRS complexes.

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