New Content Added – Patent ductus arteriosus and other new heart sounds

Strethoscope on heartbeat graph

We are pleased to announce our latest new content for paying subscribers.  We are continuing our brisk release schedule for new heart sounds, and from today can report that paying subscribers have access to videos of:

  • Atrial septal defect
  • Patent ductus arteriosus
  • Ventricular septal defect
  • Constrictive pericarditis

To whet your appetite, read on to learn more about patent ductus arteriosus:

Overview

Patent ductus arteriosus (PDA’s) represent up to 10% of the congenital heart defects in children. The male to female ratio differs in the literature with a male predominance (1:3) to female predominance (1:2). If left untreated, it has an estimated mortality of 1.8% per year in adulthood.

In adults, it tends to be an accidental finding. However, even in small PDAs which are asymptomatic there is an increased risk of endocarditis, if left untreated.

PDA is primarily confirmed with echocardiogram or cardiac MRI.  It is caused by a non-regressed communication between the pulmonary artery and the descending thoracic aorta when the normal physiological closure of the fetal ductus fails to occur.  It is one of the more common congenital cardiac defects.

This persistent vessel causes left-to-right shunting to an extent determined by both the calibre of the PDA and also the pulmonary vascular resistance.  In some patients this leads to potentially large flows between the systemic and pulmonary circulations.  As a consequence blood flow through the lungs may become excessive and lead to pulmonary engorgement.  PDA’s can also lead to Eisenmenger’s syndrome.

Clinical features:

  • Collapsing pulse (in large defects)
  • Thrusting apex beat due to volume overload
  • Left parasternal heave (if pulmonary hypertension is present)
  • Can also have an associated thrill
  • “Machinery” murmur that is continuous, which heard loudest beneath the clavicle, and may also be heard posteriorly
  • May also have a mid-diastolic tricuspid murmur in right sided volume overload
  • In some patients, evidence of heart failure

ECG changes

  • Left atrial dilatation (large PDA)
  • Left ventricular strain (large PDA)
  • Normal in small PDA

Treatment

In infants, treatment is with intravenous indomethacin – however, this is never used in adults.  The mainstay of treatment of a PDA is either catheter closure or surgical ligation, which entails a thoracotomy.

New heart sounds content

New heart sounds content added

We are pleased to announce this weeks content to our paying subscribers.

One of the biggest challenges in preparing for the MRCP PACES is encountering those rare conditions that may crop up – but are often hard to locate on the wards.

We are pleased to report our publication of four such cases for our fee-paying subscribers:

  • 4th heart sound;
  • Mixed aortic valve disease;
  • Mitral stenosis;
  • Pulmonary stenosis.

These conditions supplement our growing collection of heart sounds for you to listen to.  Paying subscribers can experience all these heart sounds played over the anatomical site where they are most audible.

4TH HEART SOUND:

This is a rare low-pitched heart sound, caused by atrial contracted against a low compliance ventricle in pre-systole. It is heard loudest in the left lateral position with the stethoscope bell.

A fourth heart sound is always pathological and is never found in healthy subjects.

Conditions associated with a 4th heart sound:

  • Hypertensive heart disease
  • Aortic stenosis
  • Left ventricular hypertrophy
  • Heart failure
  • Acute myocardial infarction
  • Ischaemic heart disease
  • Restrictive cardiomyopathy

The 4th heart sound, by definition, cannot occur in atrial fibrillation.

MIXED AORTIC VALVE DISEASE:

Aortic stenosis (along with a left bundle branch block) is associated with the fixed splitting of the 2nd heart sound. The 2nd heart sound is split, especially during expiration, due to the pulmonary valve closing prior to the aortic. In inspiration there is virtually no split (or minor) in the 2nd heart sound due to the pulmonary valve being delayed in closure.

The patient presented in our video has both aortic valve incompetence, (major) with aortic stenosis (minor), and hence both systolic and diastolic murmurs can be heard. You cannot hear any of the 2nd heart sound.

Other associated clinical features:

  • Regular pulse
  • Slowing rising pulse (AS)
  • Collapsing pulse (AR)
  • Normal JVP
  • Palpable apex beat, displaced laterally of the mid-clavicular line
  • Forceful heave that is sustained (AS)
  • Thrusting apex beat in mid-axillary line (AR)
  • Palpable systolic thrill at the displaced apex, aortic and carotid areas
  • Low pulse pressure (AS)
  • Wide pulse pressure (AR)

MITRAL STENOSIS

With stenosis of the mitral valve the left ventricle begins contraction against a valve remains open.  As such with stenosis (along with arrhythmias with short P-R intervals and tachycardia) the 1st heart sound becomes louder.

In our first case you cannot hear the mid-diastolic murmur as it is very mild, and the valve lesion was only diagnosed on echocardiogram. However, a loud 1st heart sound should make you wary of the presence of mitral stenosis.  We have three more cases of mitral stenosis coming soon in which the mid-diastolic murmur is audible.

Clinical features associated with mitral stenosis:

  • Possible malar flush
  • Irregularly irregular rhythm (or if early, sinus rhythm)
  • Possible left thoracotomy scar from mitral valvotomy
  • Normal JVP
  • Tapping cardiac impulse (isolated mitral stenosis)
  • Non-displaced apex beat (isolated mitral stenosis)
  • Left or right parasternal heave depending upon complications
  • Loud 1st HS with a subsequent opening snap
  • Mid-diastolic murmur (rumbling in nature)
      • accentuated in the left lateral position, in expiration

PULMONARY STENOSIS:

Clinical features of pulmonary stenosis include the following:

  • Normal JVP (in mild cases)
  • Giant a waves (in severe cases)
  • Possible left parasternal heave
  • Palpable systolic thrill palpated over the 2nd and 3rd intercostal spaces
  • Systolic murmur (over the pulmonary area)
  • Possibly a 4th heart sound
  • Possibly an ejection click
  • Increased volume of murmur during inspiration
  • Possibly split 2nd heart sound

Numerous textbooks will talk about radiation to the clavicle, however, this is vanishingly rare in reality.

Causes of PS include Noonan’s syndrome and carcinoid syndrome. It is also associated with Tetralogy of Fallot which (due to the over-riding aorta) results in right ventricular blood emptying straight into the aorta.

HERE’S HOW WE DO IT:

  • All our heart sounds are recorded from consenting patients with echo-confirmed disease and losslessly converted into digital format
  • After recording we digitally process sounds to remove audio artifacts, hiss and crackle without altering the basic heart sound
  • When educationally informative we provide additional slowed clips to better communicate sounds that are hard to hear
  • We then edit these clips over an actor’s chest – maintaining confidentiality and illustrating where the heart sound is best heard

Because we never use synthetic sounds and want your experience to be as realistic as possible, over-ear headphones are required.  These are very affordable and are the only way to appreciate the bass tones that are generated by heart sounds.  In-ear headphones are physically unable to reproduce these tones.

The advantages are significant.  Fee paying subscribers enjoy the following benefits:

  • Access to all our heart sounds for the duration of their subscription
  • 24/7 access, at your convenience
  • Play, rewind, re-listen as often as required.  Become an expert
  • No taking turns with several other doctors all trying to examine the same patient
  • No examiners who will undermine your confidence or criticise you in front of your peers

 

If you want to find out more about Clinical Skills Pro and our subscription packages then head over to our about us page.