Which one of the following complications is least associated with ventricular septal defects?
Correct Answer E:
Atrial fibrillation is associated more with atrial septal defects.
Ventricular septal defects are the most common cause of congenital heart disease. They close spontaneously in around 50% of cases. Non-congenital causes include post myocardial infarction.
Features:
Complications:
*aortic regurgitation is due to a poorly supported right coronary cusp resulting in cusp prolapse.
A 23-year-old man with a family history of sudden cardiac death is diagnosed as having hypertrophic obstructive cardiomyopathy.
Which one of the following is the strongest marker of poor prognosis?
Correct Answer D:
HOCM - poor prognostic factor on echo = septal wall thickness of > 3cm.
HOCM: prognostic factors: Hypertrophic obstructive cardiomyopathy (HOCM) is an autosomal dominant disorder of muscle tissue caused by defects in the genes encoding contractile proteins. Mutations to various proteins including beta-myosin, alphatropomyosin and troponin T have been identified. Septal hypertrophy causes left ventricular outflow obstruction. It is an important cause of sudden death in apparently healthy individuals.
Poor prognostic factors:
A 65-year-old man with no significant past medical history is admitted to the Emergency Department. His ECG is consistent with an anterior myocardial infarction. Unfortunately he develops cardiac arrest shortly after arriving in the department.
What is the most common cause of death in patients following a myocardial infarction?
Myocardial infarction: complications:
Patients are at risk of a number of immediate, early and late complications following a myocardial infarction (MI).
1- Cardiac arrest:
This most commonly occurs due to patients developing Ventricular Fibrillation and is the most common cause of death following a MI. Patients are managed as per the ALS protocol with defibrillation.
2- Cardiogenic shock: If a large part of the ventricular myocardium is damaged in the infarction the ejection fraction of the heart may decrease to the point that the patient develops cardiogenic shock. This is difficult to treat. Other causes of cardiogenic shock include the 'mechanical' complications such as left ventricular free wall rupture as listed below. Patients may require inotropic support and/or an intra-aortic balloon pump.
3- Chronic heart failure:
As described above, if the patient survives the acute phase their ventricular myocardium may be dysfunctional resulting in chronic heart failure. Loop diuretics such as furosemide will decrease fluid overload. Both ACE inhibitors and beta-blockers have been shown to improve the long-term prognosis of patients with chronic heart failure.
4- Tachyarrhythmias:
Ventricular fibrillation, as mentioned above, is the most common cause of death following a MI. Other common arrhythmias including ventricular tachycardia.
5- Bradyarrhythmias:
Atrioventricular block is more common following inferior myocardial infarctions.
6- Pericarditis:
Pericarditis in the first 48 hours following a transmural MI is common (c. 10% of patients). The pain is typical for pericarditis (worse on lying flat etc), a pericardial rub may be heard and a pericardial effusion may be demonstrated with an echocardiogram.
7- Dressler's syndrome tends to occur around 2-6 weeks following a MI. The underlying pathophysiology is thought to be an autoimmune reaction against antigenic proteins formed as the myocardium recovers. It is characterized by a combination of fever, pleuritic pain, pericardial effusion and a raised ESR. It is treated with NSAIDs.
8- Left ventricular aneurysm:
The ischaemic damage sustained may weaken the myocardium resulting in aneurysm formation. This is typically associated with persistent ST elevation and left ventricular failure. Thrombus may form within the aneurysm increasing the risk of stroke. Patients are therefore anticoagulated.
9- Left ventricular free wall rupture:
This is seen in around 3% of MIs and occurs around 1-2 weeks afterwards. Patients present with acute heart failure secondary to cardiac tamponade (raised JVP, pulsus paradoxus, diminished heart sounds). Urgent pericardiocentesis and thoracotomy are required.
10- Ventricular septal defect:
Rupture of the interventricular septum usually occurs in the first week and is seen in around 1-2% of patients.
Features: acute heart failure associated with a pan-systolic murmur. An echocardiogram is diagnostic and will exclude acute mitral regurgitation which presents in a similar fashion. Urgent surgical correction is needed.
11- Acute mitral regurgitation:
More common with inferoposterior infarction and may be due to ischaemia or rupture of the papillary muscle. An early-to-mid systolic murmur is typically heard. Patients are treated with vasodilator therapy but often require emergency surgical repair.
A 62-year-old man is admitted with pyrexia and found to have infective endocarditis.
Which one of the following is most associated with a good prognosis?
Correct Answer C:
Infective endocarditis - streptococcal infection carries a good prognosis.
Infective endocarditis: prognosis and management:
Mortality according to organism:
Indications for surgery:
You are called to assess a man who has collapsed in the clinic waiting room. A staff nurse has already bleeped the cardiac arrest team. On arrival the man is laid on his back. You open the airway with a head-tilt chin lift – after assessing for 10 seconds there are no signs of breathing.
What is the most appropriate next step?
The 2010 guidelines do not support the concept of 'checking for circulation'; absence of breathing, in a nonresponsive individual, is now used as the main sign of cardiac arrest. In reality most medical professionals will check for a carotid pulse whilst assessing breathing, but in this scenario to wait a further 10 seconds before starting chest compressions is not justifiable. Please see the link to the BLS guidelines.
Adult advanced life support:
The joint European Resuscitation Council and Resuscitation Council (UK) 2010 guidelines do not alter significantly from the 2005 guidelines. Please see the link for more details, below is only a very brief summary of key points / changes.
Major points include :
electrical activity (PEA):
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