Cardiology Flashcards
Which valvular abnormality is a mid diastolic murmur?
Mitral stenosis.
Mid-late diastolic murmur (best heard in expiration)
loud S1
Features of cardiac syndrome X?
- Angina-like chest pain on exertion
- ST depression on exercise stress test
- but normal coronary arteries on angiography
continuous ‘machinery’ murmur?
Patent ductus arteriosus.
Mechanism of action of ACE inhibitors?
Inhibits the conversion angiotensin I to angiotensin II
→ decrease in angiotensin II levels → to vasodilation and reduced blood pressure
→ decrease in angiotensin II levels → reduced stimulation for aldosterone release → decrease in sodium and water retention by the kidneys.
Renoprotective mechanism:
angiotensin II constricts the efferent glomerular arterioles.
ACE inhibitors therefore lead to DILATION of the EFFERENT arterioles → reduced glomerular capillary pressure → decreased mechanical stress on the delicate filtration barriers of the glomeruli
Side effect of ACE-inhibitors?
- Cough
occurs in around 15% of patients and may occur up to a year after starting treatment
thought to be due to increased bradykinin levels - Angioedema: may occur up to a year after starting treatment
- Hyperkalaemia
- First-dose hypotension: more common in patients taking diuretics
Cause of JVP irregular cannon wave?
Complete heart block.
Causes of JVP regular cannon wave?
- Ventricular tachycardia (with 1:1 ventricular-atrial conduction)
- Atrio-ventricular nodal re-entry tachycardia (AVNRT)
Feature of Aortic regurgitation?
Early diastolic murmur.
- Collapsing pulse
- Wide pulse pressure
- Quincke’s sign (nailbed pulsation)
- De Musset’s sign (head bobbing)
- Mid-diastolic Austin-Flint murmur in severe AR - due to partial closure of the anterior mitral valve cusps caused by the regurgitation streams
How does BNP help heart failure?
- Decreases cardiac afterload.
- Diuretic and natriuretic
- Suppresses both sympathetic tone and the renin-angiotensin-aldosterone system
What can cause a DVT to lead to a stroke?
Patent foramen ovale (hole between left atrium and right atrium) may allow embolus (e.g. from DVT) to pass from right side of the heart to the left side leading to a stroke - ‘a paradoxical embolus’.
Mainstay of treatment for pulmonary arterial hypertension? (PAH)
If there is a negative response to acute vasodilator testing (the vast majority of patients):
- Prostacyclin analogues: Treprostinil, Iloprost
- Endothelin receptor antagonists: Bosentan, Ambrisentan
- Phosphodiesterase inhibitors: Sildenafil
If there is a positive response to acute vasodilator testing (a minority of patients)
- Oral calcium channel blockers
Features of WPW on ECG?
WPW syndrome is caused by a congenital accessory conducting pathway between the atria and ventricles leading to atrioventricular re-entry tachycardia (AVRT). As the accessory pathway does not slow conduction AF can degenerate rapidly to VF.
- Short PR interval
- Wide QRS complexes with a slurred upstroke - ‘Delta Wave’
- Left axis deviation if right-sided accessory pathway
(in the majority of cases, or in a question without qualification, WPW syndrome is associated with left axis deviation) - Right axis deviation if left-sided accessory pathway
Management of WPW syndrome?
Definitive treatment: radiofrequency ablation of the accessory pathway.
Medical therapy: Sotalol***, Amiodarone, Flecainide
(Sotalol should be avoided if there is coexistent atrial fibrillation as prolonging the refractory period at the AV node may increase the rate of transmission through the accessory pathway, increasing the ventricular rate and potentially deteriorating into ventricular fibrillation)
What is Eisenmenger’s syndrome?
Eisenmenger’s syndrome describes the reversal of a left-to-right shunt in a congenital heart defect due to pulmonary hypertension. This occurs when an uncorrected left-to-right leads to remodeling of the pulmonary microvasculature, eventually causing obstruction to pulmonary blood and pulmonary hypertension.
Features:
- Original murmur may disappear
- Cyanosis
- Clubbing
- Right ventricular failure
- Haemoptysis, embolism
What is the drug management for chronic heart failure?
- The first-line treatment for all patients is both an ACE-inhibitor and a beta-blocker.
(ACE-inhibitors and beta-blockers have no effect on mortality in heart failure with preserved ejection fraction).
- The standard second-line treatment is an aldosterone antagonist (mineralocorticoid receptor antagonists). Examples include spironolactone and eplerenone.
increasing role for SGLT-2 inhibitors in the management of heart failure with a reduced ejection fraction.
They reduce glucose reabsorption and increase urinary glucose excretion. (canagliflozin, dapagliflozin and empagliflozin)
- Third-line treatment should be initiated by a specialist. Options include ivabradine, sacubitril-valsartan, hydralazine in combination with nitrate, digoxin and cardiac resynchronisation therapy.
- Offer annual influenza vaccine
- Offer one-off pneumococcal vaccine
adults usually require just one dose but those with asplenia, splenic dysfunction or chronic kidney disease need a booster every 5 years.
Most common organism for infective endocarditis in IVDU?
Staphylococcus aureus is commonly associated with infective endocarditis amongst IVDU.
Typically causing tricuspid lesions.
Most common organism involved in prosthetic valve endocarditis?
Staphylococcus epidermidis
commonly colonize indwelling lines and are the most cause of endocarditis in patients following prosthetic valve surgery, usually the result of perioperative contamination.
After 2 months the spectrum of organisms which cause endocarditis return to normal (i.e. Staphylococcus aureus is the most common cause)
Treatment for eclampsia?
Magnesium sulphate is used to both prevent seizures in patients with severe pre-eclampsia and treat seizures once they develop.
- In eclampsia an IV bolus of 4g over 5-10 minutes should be given followed by an infusion of 1g / hour.
- Urine output, reflexes, respiratory rate and oxygen saturations should be monitored during treatment
respiratory depression can occur: calcium gluconate is the first-line treatment for magnesium sulphate induced respiratory depression.
Monitoring reflexes, particularly deep tendon reflexes (DTR), and respiratory rate are crucial during magnesium administration. Loss of DTRs may indicate magnesium toxicity, which can lead to muscle weakness, respiratory depression, and even respiratory arrest if not addressed promptly. Similarly, monitoring the patient’s respiratory rate is essential as a decreasing rate can be an early sign of magnesium toxicity.
Drug for Torsades de pointes?
Torsades de pointes is a specific form of polymorphic ventricular tachycardia, characterized by a twisting QRS complex around the isoelectric baseline.
It can be precipitated by various factors, including electrolyte imbalances, medications, and underlying cardiac conditions.
Intravenous magnesium sulphate is the first-line treatment for torsades de pointes especially when the patient is hemodynamically stable (normal BP and no signs of HF).
How long for DAPT following placement of a drug-eluting stent?
12 months of dual antiplatelet therapy after placement of a drug-eluting stent (DES).
Initial blind therapy for infective endocarditis including native and prosthetic valves?
- Native valve:
Amoxicillin, consider adding Gentamicin. - If penicillin allergic, MRSA or severe sepsis:
Vancomycin + Gentamicin - If prosthetic valve:
Vancomycin + Rifampicin + Gentamicin
Classic features of cardiac tamponade?
Cardiac tamponade is characterized by the accumulation of pericardial fluid under pressure.
Classical features - Beck’s triad:
1. Hypotension
2. Raised JVP
3. Muffled heart sounds
- Dyspnoea
- Tachycardia
- An absent Y descent on the JVP - this is due to the limited right ventricular filling
- Pulsus paradoxus - an abnormally large drop in BP during inspiration
- ECG: electrical alternans
Management:
Urgent pericardiocentesis
What are the indications for ICDs?
Implantable cardiac defibrillators (ICDs) are used to prevent sudden cardiac death in patients at risk of life-threatening ventricular arrhythmias.
- Long QT syndrome
- HOCM
- Previous cardiac arrest due to VT/VF
- Previous myocardial infarction with non-sustained VT on 24 hr monitoring, inducible VT on electrophysiology testing and ejection fraction < 35%
- Brugada syndrome
Adverse effects of thiazide like diuretics?
Thiazide diuretics work by inhibiting sodium reabsorption at the proximal part of the distal convoluted tubule (DCT) by blocking the thiazide-sensitive Na+-Cl− symporter.
Common adverse effects:
- Dehydration
- Postural hypotension
- Hypokalaemia: increased delivery of sodium to the distal part of the distal convoluted tubule → increased sodium reabsorption in exchange for potassium and hydrogen ions
- Hyponatraemia
- Hypercalcaemia: the flip side of this is hypocalciuria, which may be useful in reducing the incidence of renal stones.
- Gout
- Impaired glucose tolerance
- Impotence
Which condition is growing Streptococcus bovis and
the subtype Streptococcus gallolyticus most linked with in infective endocarditis?
Streptococcus bovis is associated with colorectal cancer.
the subtype Streptococcus gallolyticus is most linked with colorectal cancer.
