Most commonly identified genetic mutations in those suffering from CPVT occur in -
The most commonly identified genetic mutation in CPVT is a mutation in the RYR2 gene that encodes the cardiac ryanodine receptor, responsible for releasing calcium from the sarcoplasmic reticulum.
TYPES OF CPVT AND ASSOCIATED GENE MUTATIONS
CPVT1: RYR2 mutations
CPVT2: CASQ2 mutations
CPVT3: TECRL encoding Trans-2,3-enoyl-CoA reductase-like protein.
CPVT 4: CALM1 encoding Calmodulin
CPVT 5: TRDN encoding Triadin
All of the following are correct for CPVT -1 EXCEPT –
Mutations in this RYR2 gene lead to an autosomal dominant form of CPVT known as CPVT1.
Which gene encodes Phospholamban ?
Phospholamban is a micropeptide protein. In humans Phospholamban is encoded by the PLN gene.
Mutations in this gene encoding phospholamban can cause -
Phospholamban is a micropeptide protein. In humans Phospholamban is encoded by the PLN gene. Mutations in phospholamban gene are a cause of inherited human dilated cardiomyopathy with refractory congestive heart failure
Which of the following is more sensitive index of cardiac function –
More sensitive index of cardiac function is the ejection fraction. Ejection Fraction is calculated by ratio of stroke volume to end-diastolic volume (normal value = 67 ± 8%).
Best method to measure Ejection Fraction -
Cardiac MRI is now considered the best method to measure Ejection Fraction.
All of the following are determinants of Ventricular Preload EXCEPT –
Ventricular Afterload Determinants -
- Systemic vascular resistance
- Elasticity of arterial tree
- Arterial blood volume
- Ventricular wall tension
- Ventricular radius
- Ventricular wall thickness
Ventricular Preload Determinants
- Blood volume
- Distribution of blood volume
- Body position,
- Intrathoracic pressure,
- Intrapericardial pressure
- Venous tone,
Pumping action of skeletal muscles
Bachmann's bundle conducts the impulse from –
Bachmann's bundle or the interatrial band that conducts the impulse directly from the right atrium to the left atrium.
Thebesian veins drain into -
Thebesian veins drain directly into any of the four chambers of the heart.
Anatomic landmark between the coronary sinus and the great cardiac vein –
The Vieussens valve of the coronary sinus is a valve and anatomic landmark between the coronary sinus and the great cardiac vein.
Thebesian valve- The valve of the Coronary Sinus - medial to the inferior vena cava opening, just superior to the septal leaflet of the tricuspid valve.