Histology
Cardiac myocytes typically have how many nuclei?
Single nucleas to the centre of the cell
An irregularly irregular pulse on examination indicates
Atrial fibrillation
Digoxin’s ability to reduce conduction through the AV node is particularly useful in.
Digoxin helps control ventricular response in atrial fibrillation/flutter.
what does M. Ismails heart beat sound like
lub dub lub dub lub dub lub dub
Angelo decides to come to placement wipeout drunk what is the first thing you will do
1) talk to him
2) if the problem persists report him
Which junction provides electrical connectivity between cardiac cells?
Gap junctions,
They can be large or small. They provide contact between cardiac cells, allowing electrical communication so that waves of depolarisation spread rapidly over the entire heart, passing from cell to cell
Which of the following statements about palpitations is TRUE?
A. Always indicate heart disease
B. Can be caused by arrhythmia, anxiety, or systemic conditions
C. Are only due to tachycardia
D. Never occur in athletes
Palpitations are multifactorial — cardiac, metabolic, psychological, and pharmacological causes exist.
The direct vascular effect of Digoxin is best described as:
The direct effect is on blood vessels is vasoconstriction.
However it also has an effect in reducing the systemic vascular resistance.
It also has a small diuretic effect on the kidneys, which is beneficial in heart failure patients.
A fixed splitting of S2 is most commonly associated with:
Atrial septal defect
increased right-sided flow delays pulmonary valve closure, producing fixed (non-variable) S2 splitting.
Which of the following non-cardiac conditions is a frequent cause of palpitations?
A. Hypothyroidism
B. Hyperthyroidism
C. Addison’s disease
D. Hypocalcaemia
b) Increased thyroid hormone enhances sympathetic activity, leading to sinus tachycardia and palpitations.
Troponin 1 has a strong affinity for and why?
Actin,
Troponin is a protein molecule attached intermittently along the sides of the Tropomyosin molecules. They are complexes of 3 loosely bound protein subunits. Each subunit plays a specific role in muscle contraction,
The high affinity to actin keeps the muscle in a relaxed state until a nerve impulse causes calcium to bind to the troponin-C.
In atrial fibrillation, Digoxin slows the ventricular rate by (doing what)
Digoxin increases vagal (parasympathomimetic) activity, reducing AV nodal conduction and ventricular rate.
the ability of digoxin to activate vagal efferent nerves to the heart helps in reducing the ventricular rate which is driven by a high atrial rate (parasympathomimetic effect).
The vagal activation can reduce the conduction of electrical impulses within the AV node, blocking some of the impulses. Digoxin also increases the effective refractory period within the AV node.
In addition to its cardiac effects, Digoxin has which beneficial renal action?
Digoxin mildly increases renal perfusion and diuresis useful in managing oedema in heart failure.
what are the s1 and s2 heart sounds
S1 is the first heart sound, or "lub," caused by the closing of the mitral and tricuspid valves at the beginning of ventricular systole, marking the start of the heart's contraction.
S2 is the second heart sound, or "dub," caused by the closing of the aortic and pulmonary valves at the end of systole, marking the start of diastole
The most common cardiac cause of palpitations is:
Atrial fibrillation produces an irregularly irregular rhythm often perceived as palpitations.
Which of the following is NOT a component of the intercalated disc?
A. Gap junctions
B. Desmosomes
C. Fascia adherens
D. Tight junctions
D. Tight junctions
Intercalated discs contain three types of cell junctions,
- Fascia adherens/ anchoring junctions: Where the actin filaments attach thin filaments in the muscle sarcomere to the cell
- Desmosomes: Sites of strong adhesion that help keep the muscles cells connected when they contract
- Gap junctions: Can be large or small. They provide contact between cardiac cells, allowing electrical communication so that waves of depolarisation spread rapidly over the entire heart, passing from cell to cell
Palpitations in a patient with normal ECG and thyroid function are most likely due to:
A. Anxiety or panic disorder
B. Ventricular ectopy
C. Atrial fibrillation
D. Heart block
Anxiety and panic attacks are common non-cardiac causes of perceived palpitations.
Which of the following best describes Digoxin’s mechanism in improving cardiac contractility?
A. Blocks β-adrenergic receptors
B. Inhibits Na⁺/K⁺-ATPase, increasing intracellular calcium
C. Stimulates adenylyl cyclase
D. Activates Na⁺/K⁺ pump
B) By inhibiting Na⁺/K⁺-ATPase, Digoxin raises intracellular Na⁺, reducing Na⁺/Ca²⁺ exchange and increasing intracellular Ca²⁺ giving stronger contractions.
The murmur of aortic stenosis typically radiates to:
Aortic stenosis produces a harsh systolic murmur radiating to the neck.
Troponin T in cardiac muscle binds in the sarcoplasmic myocyte complex to make it shorter which is why sarcoplasmic reticulum in cardiac muscle is as extensive as that in skeletal muscle.
true or false
False.
I made half of that up.
The sarcomere pattern (striations) in cardiac muscle is due to
Arrangement of actin and myosin filaments
Palpitations due to premature ventricular contractions (PVCs) are often described as:?
PVCs often cause an early beat followed by a compensatory pause, perceived as a "missed" heartbeat.
what is the dosage of digoxin
After the initial dose, the usual daily dose for adults and children over 10 years is 125 micrograms to 250 micrograms daily.
The first time you take digoxin you may be asked to take several tablets (or amounts of liquid) as a single dose – this is called the initial dose.
Your doctor will do a blood test after the initial dose to see how it's worked for you. They'll then recommend a daily dose. Sometimes this will be split into doses to take throughout the day.
A late diastolic murmur that increases with inspiration suggests.
Tricuspid stenosis
This is because inspiration increases venous return to the right side of the heart, leading to increased blood flow across the tricuspid valve during diastole, which accentuates the murmur
Inspiration increases negative pressure in the chest, which draws more blood into the right side of the heart, and this increased volume of blood flow across the tricuspid valve during diastole creates a more audible murmur
M.Ismail has just carried ISOC football to a win again. He is resting after the match and reports a regular and slow pounding in his head.
What might cause this?
A slow, regular rhythm felt as pounding may represent sinus bradycardia.
a slow heart rhythm where the sinoatrial (SA) node fires electrical signals at a rate below 60 beats per minute, causing a heart rate below 60 bpm in adults. It is common and often harmless in fit individuals, especially athletes and during sleep