Cardiology Clinical Flashcards
What is myocarditis?
Inflammation of the myocardium
What are the causes of myocarditis?
- viral - coxsackie B, HIV
- Bacterial - diphtheria, HIV
- Lyme disease
- Chagas disease, toxoplasmosis
- Autoimmune
- Doxurubicin
What are the indications for surgery for infective endocarditis?
Severe valvular incompetence Aortic abscess (recognised as there is lengthening of the PR interval) Resistent infection Cardiac failure Recurrent emboli
What is a MUGA scan and when is it used?
Multi gated acquisition scan
Used to assess myocardial perfusion and myocardial viability (useful before and after cardiotoxic drugs to assess left ventricular ejection fraction)
When is a cardiac mri useful?
Structural images of the heart - useful in congenital heart disease, determining right and left mass and differentiating forms of cardiomyopathy
What is the definitive management of wolf parkinson white syndrome?
Radio-frequency ablation of the accessory pathway
What is a normal QT interval?
Less than 430 in males and less than 450 in females
What electrolyte abnormalities cause long QT syndrome?
Hypocalcaemia
Hypokalaemia
Hypomagnesiumemia
What drugs can cause long QT?
Amioderone Tricyclics (especially citalopram) Erythromycin Haloperidol Ondansetron
Which bacteria most commonly causes endocarditis in patients with colorectal cancer?
Streptococcus bovis
What is the most common cause of infective endocarditis?
Staph aureus
What is 1st degree heart block?
PR interval over 0.2 seconds
Usually asymptomatic
What is mobitz type 1 av bock?
PR interval becomes progressivly longer until you get a dropped beat
May get syncope
What is mobitz type 2 heart block?
Random dropped beats with usually a ratio of 2: 1 or 3:1.
Tend to get symptoms including syncope and chest pain
What is third degree heart block?
No relationship between atria and ventricles (av node blocked completely) very low heart rate
What happens to the pulse in complete heart block?
Wide pulse pressure
What is the target INR for a venous thromboembolism?
- 5
3. 5 if recurrent
What is the target INR for atrial fibrillation?
2.5
What is the treatment for prevention of angina?
- Beta blocker or calcium channel blocker
If not tolerated/contraindicated - Long acting nitrate eg isosorbine mononitrate
- Nicorandil
- Ivabradine
What is the difference between paroxysmal and persistent AF?
Paroxysmal - 2 or more episodes that are self terminating
Persistent - 2 or more episodes that are not self terminating
How do statins work?
Inhibit HMG CoA reductase - which is the rate limiting enzyme in hepatic cholesterol synthesis
What is the treatment for major bleed in a patient who is taking warfarin?
- Stop warfarin
- IV vitamin K 5mg
- Prothrombin complex concentrate
How do thiazide diuretics work?
Inhibiting sodium reabsorption at the beginning of the distal convoluted tubule by blocking the Na/Cl symporter.
What type of pulse in associated with aortic stenosis?
Slow rising pulse
Narrow pulse pressure
What is malignant hypertension?
Blood pressure over 200/130. Can lead to cerebral oedema and encephalopathy as well as fibrinoid necrosis of blood vessels leading to retinal haemorrhages, exudates, proteinuria and haematuria due to renal damage.
What is the management of malignant hypertension?
Reduce diastolic BP by no lowere than 100mmHG within 12 - 24 hours. Best rest
- Atenolol
- IV sodium nitroprusside/labetolo if severe.
How do you manage aortic stenosis?
If asymptomatic then observe if symptomatic then valve replacement.
What is the definition of pulmonary hypertension?
Resting mean pulmonary artery pressure of 25mmHg or more
What is the definitive investigation for pulmonary hypertension?
Right heart catheterisation to measure pulmonary pressure.
What is the role of vasoreactivity testing in pulmonary hypertension?
Vasoreactivity testing (performed with nitric oxide) helps differentiate patients. 1. Those who respond (reduction of at least 10mmHg to less than 40mmHg without a fall in cardiac output) may respond to long term high dose calcium channel blockers eg diltiazem
What is the most useful non invasive test for pulmonary hypertension?
Echocardiogram
What treatments are available for pulmonary hypertension?
- Calcium channel blockers (only in patiemts with a response to vasoreactivity testing)
- Postacyclin analogues eg iloprost - can be given IV/SC
- Endothelin recpetior antagonist eg bosentan
- Phosphodiesterase 5 inhibitors eg sildanefil (viagra)
- Heart - lung transplant
In STEMI what is the window for PCI?
120 minutes - if not possible then alteplase should be given. If a repeat ECG at 90 minutes does not show resolution then patient will need to be transferred to a PCI centre
What causes cannon waves on JVP?
The right atrium contracting against a closed tricuspid valve - can be regular or intermittent.
Regular = VT with 1: 1 ventricular atria conduction
Atrio-ventricular nodal re entry tachycardia
Irregular = Complete heart block
What is a cholesterol embolisation?
Occurs when cholesterol is released from an atherosclerotic plaque and travels as an embolism and causes an obstruction
Usually secondary to vascular surgery or angiography. Causes purpura, livido reticularis and eosinophilia as well as renal failure
What is brugada syndrome?
Inherited cardiovascular disease which may present with sudden cardiac death. Autosomal dominant.
What ECG changes are seen in brugada syndrome?
Convex ST segment elevation on over 2mm in 1 or more of V1 - V3 followed by a negative T wave
Partial right bundle branch block
(ECG changes may be more apparant following administration of flecainide)
What is the management of brugada syndrome?
Implantable cardioverter - defibrillator
Under what pottasium do you tend to see ECG changes consistend with hypokalaemia?
2.7mmol/L
What are the ECG changes associated with hypokalaemia?
U waves Small T waves Long PR interval ST depression Long QT
What is the most common form of cardiomyopathy?
Dilated cardiomyopathy
When do you see pulsas alterans?
Left ventricular failure