During inspiration the aortic component of the second heart sound is heard about 0.02 to 0.08 seconds before the pulmonary component. The reason is as follows:

During inspiration, a negative intrathoracic pressure is created to inhale air into the lungs
This creates a vaccum effect which results in increased venous return to the right side of the heart
Hence the right ventricle takes a longer time to eject the blood into the pulmonary system
Also since pulmonary vasculature expands in capacity, lower amount of blood flows into the left atrium
Hence the left ventricle takes a …

The pulmonary valve remains open for some time even after the right ventricular pressure becomes equal to pulmonary artery pressure at end of systole
This time interval is known as hangout interval

Why does pulmonary valve remain open even after pressure equilisation?

According to Newton’s first law of motion, every body continues to move at constant speed unless acted upon by an external force
In this case, the blood continues to flow from the right ventricle even after the the pressure in the right ventricle and the pulmonary artery becomes equal
Just like a rolling …

Doxorubicin is an anti cancer drug which produces cardiotoxicity as side effect
Clinical features

Acute presentation with hypotension, arrhythmias, bundle branch block, ST changes
Delayed presentation with features of congestive cardiac failure

Pathology

Development of cardiac toxicity is due to cardiomyopathy

Risk increases beyond doses of 550mg/m2

There is bilateral symmetrical enlargement of the adrenals
Shape of the gland is preserved
Patient is usually asymptomatic
Some cases present with adrenal insufficiency
Diagnosis is by CT scan and CT directed biopsy

Alternate names :

Extranodal natural killer cell lymphoma
Nasal-type NK lymphoma
NK/T-cell lymphoma
Polymorphic/malignant midline reticulosis

It is a cutaneous lymphoma seen mostly in Korea
It is said to be the most common form of cutaneous lymphoma after mycosis fungoides
It is associated with Epstein Barr virus

Atrial fibrillation has been classified into 4 categories based on duration by the American heart association. They are:

Paroxysmal AF – Lasting upto 7 days. But usually it undergoes spontaneous resolution within 48 hours
Persistent AF – Lasting more than 7 days upto 1 year
Long standing persistent AF – If an AF lasts more than 1 year and we are planning to do rhythm control treatment (chemical cardioversion / electrical cardioversion / ablation of the excitation focus)
Permanent AF – If AF lasts for more than 1 year and we are not planning to do …

Radiological signs seen in mitral stenosis are:

Backward displacement of esophagus by enlarged left atrium (in lateral view X-ray)
Enlarged left atrium in AP view X-ray (Blood pools in the left atrium as it is unable to pass into the left ventricle. This results in progressive dilatation.)
Straightening of left heart border
Double shadow due to enlarged left atrium
Splaying of carina (The left main bronchus is lifted up by the enlarged left atrium)
Prominent upper zone pulmonary veins (Inverted moustache sign /  Antler’s horn sign / Cephalisation pulmonary of blood flow)
Enlarged pulmonary trunk (This occurs …

Cardiac features of carcinoid syndrome are tricuspid regurgitation, pulmonary stenosis and right ventricular endocardial plaques
These result in heart failure

Pattern of cardiac involvement in carcinoid syndrome

Serotonin which is secreted in excess amounts in carcinoid syndrome is the cause of the cardiac manifestations
It is metabolised in the lungs and liver
So in most cases of carcinoid syndrome, there is no involvement of the heart
But in cases of metastatic carcinoid syndrome involving liver and the lungs, the heart is directly exposed to huge quantities of serotonin
Right heart lesions are seen in liver metastasis and …

Pupil characteristics can be used to identify the cause of coma in a patient. It also helps in determining the treatment. The important pupillary signs are given below:

Pupil
Condition

Pinpoint pupils
Pontine lesion / morphine poisoning

Moderately dilated, non reactive, fluctuating
Mid brain lesions

Unilateral dilated, non reactive
Third nerve damage – due to transtentorial herniation of temporal lobe / traction of third nerve against posterior cerebral artery

Bilateral dilated, non reactive
Terminal states / Ischemic brain damage / Atropine / Belladonna poisoning

Small, equal, reactive
Toxic / Metabolic causes of coma

Barium swallow – Right anterior oblique view chest x-ray – showing normal indentations of oesophagus
Click on image for an enlarged view

The normal indentations of the esophagus seen in a right anterior oblique view during barium swallow are made by (from above downwards):

Aortic arch – 22.5 cm from incisor teeth
Left bronchus – 27.5 cm from incisor teeth
Left atrium

Clinical importance:

In olden days, when echocardiography was not available, this was used to detect left atrial enlargement in cases of mitral stenosis
When left atrium is enlarged, it may compress on the esophagus and cause dysphagia – …