Cardio Flashcards
What is the Bernheim effect and the reverse Bernheim effect?
● The Bernheim effect: under normal circumstances there is a slight
displacement of the inner ventricular septum into the right
ventricular cavity because of the higher pressures on the left side of
the heart.
● The reverse Bernheim effect: occurs when there is right ventricular
overload, when displacement of the intraventricular septum into the
left ventricular cavity occurs.
Kindly explain why the left side of the heart is more prone to disease.
It is presumably related to thickness of the left ventricle and workload
compared to the right side. Diseases such as hypertension much more
frequently affect the left side.
Is it always necessary to examine the cardiovascular system of a
patient in the 45° incline of the head end? Other than convenience for
examining the jugular venous pressure (JVP), does this position have
any other advantage?
No, it is mainly done for convenience; the JVP is normally just visible
at this angle. The top of the JVP must be seen and therefore the
position is irrelevant.
If the JVP is not visible when the patient is in the upright position, can
one presume it is not raised?
Probably, unless it is very high and the top of the column is
behind the right ear. The JVP is acting like a U tube and does not
have to be measured at 45° because the measurement is a vertical one
(normal 3–4 cm above the manubrium sternum). 45° is convenient in
that the JVP should just be seen at this angle. Sitting the patient
up can allow a very high venous pressure to be seen whereas
lying the patient flat can allow a low venous pressure to become
visible.
The mitral area (of auscultation) normally corresponds with the apex
beat. When the heart is dilated and the apex beat is shifted laterally, will
the mitral area follow the apex beat to its new location or remain at the
place where the apex beat is normally situated?
The mitral area follows the apex beat, often into the axilla.
Please explain in detail how to measure the pulsus paradoxus using
a sphygmomanometer.
The pulse pressure (the difference between systolic and diastolic blood
pressure) falls during inspiration. If you blowup the sphygmoman ometer
cuff to roughly the mid-point between diastolic and systolic pressure, the
mercury column can be seen to be moving and falling on inspiration; an
exaggerated fall greater than 10 mmHg can be seen in pulsus paradoxus
What is the difference between dicrotic pulse and pulsus bisferiens?
Pulsus bisferiens has two systolic peaks: the percussion and tidal waves.
In dicrotic pulse, the second peak is in diastole immediately after the
second heart sound
Why does the radial pulse become more prominent when the hand is
lifted overhead?
Raising the arm does make the radial pulse easier to feel and this
is more obvious with a large-volume pulse, which occurs in aortic
regurgitation.
Please explain the mechanism of a collapsing pulse. Which is the best
artery to elicit it: radial, brachial or carotid?
A collapsing pulse is due to an increased stroke volume, which gives
quick distension of the peripheral arteries followed by regurgitation of
blood back into the left ventricle, which gives a rapid fall, i.e. a quick
rise followed by collapse. The brachial is probably the best artery to
palpate.
What is the mechanism of Durozier’s sign?
This is a femoral bruit (‘pistol shot’) due to a large volume pulse.
What effects do aortic stenosis, aortic regurgitation and coarctation of the
aorta have on systolic and diastolic blood pressure, and why do they
produce these effects?
Aortic stenosis can produce a low systolic pressure with a normal
diastolic pressure because of outflow obstruction to the left ventricle
(systolic) but normal peripheral resistance (diastolic). Aortic
regurgitation produces normal or high systolic pressure because of
unimpeded left ventricular emptying with low diastolic pressure due to
a rapid fall in peripheral flow. Hypertension in coarctation is due to
reduced renal flow (the Goldblatt effect).
In the section headed ‘Pulsus bisferiens’ (K&C 7e, p. 691) what do
‘percussion wave’ and ‘tidal wave’ mean? An illustration here would be
helpful.
The percussion wave is the first wave produced by the transmission of
the left ventricular pressure in early systole. With recoil of the vascular
bed a second weaker wave (tidal) occurs which can be felt in the radial
artery in the presence of slow ventricular emptying, e.g. in mixed aortic
valve disease. A double pulse is bisferiens
When examining a patient’s carotid pulse, why should we not palpate
both carotids at once? Is it because it might block the blood supply to the
brain?
Yes, palpating each carotid separately is safer (one side may have a
stenosis/atheroma) and might provide more information, e.g. right
carotid sinus massage decreases the sinus node discharge. In addition,
carotid sinus syncope can occur, which can impair cerebral perfusion in
some elderly patients, causing loss of consciousness.
How can I differentiate between jugular and arterial pulsation in the neck
practically?
● You can look for the double pulsation of the jugular venous pulse.
● You can feel the arterial pulse at the same time as you look at the
jugular venous pulsation.
● The point at which the venous column is seen varies with the position
of the patient.
● Pressure on the liver raises the jugular venous pressure, which can be
used to make sure that it is the venous wave (hepato-jugular reflux).
Can you please help me with this: ‘Thrusting due to mitral or aortic
regurgitation. Heaving due to aortic stenosis and systemic hypertension.
There is often confusion about the terms thrusting and heaving’.
Another book I read considers aortic stenosis and hypertension for
thrusting and mitral/aortic regurgitation for heaving. Who should I go
with? Thank you.
There is indeed confusion regarding the terms ‘thrusting’ and ‘heaving’.
We ourselves have changed the terms used to describe the apex beat over
the seven editions! You are also correct in saying that different terms
are used by different authors. In the 7th edition we do not use the term
‘thrusting’. Sustained (heaving) apex beat occurs in pressure overload
situations, e.g. in aortic stenosis; forceful occurs with volume overload,
e.g. aortic regurgitation.
Where is the best place on the precordium to auscultate a split-second
heart sound?
In the so-called pulmonary area: left substernal edge, second intercostal
space.
What is the mechanism by which murmurs of mitral valve prolapse
(MVP) and hypertrophic cardiomyopathy (HC) are accentuated by
standing or the Valsalva manoeuvre?
Standing or the ‘strain phase’ of the Valsalva manoeuvre decreases the
left ventricular volume which increases the intensity and the duration
of the murmur. ‘Squatting’ increases left ventricular volume and the
murmur becomes shorter and softer.
What is the correct procedure for a fluoroscopy and why is this essential
for the insertion of cardiac catheter, pacemaker and prosthetic valve?
Fluoroscopy is dynamic radiography. X-rays are being taken continually
so that the image is moving, not static as in a chest X-ray. Radiation hazards limit the time used but it is invaluable in placing catheters etc. in
the correct position.
What is the role of amiodarone in the acute management of asystole or
pulseless electrical activity (PEA)?
There is no role for amiodarone in asystole. Vasopressin does seem to be
helpful.
Is there any contraindication to the use of microwaves or mobile
phones in patients with pacemakers?
None with microwaves. Mobile phones should not be held right next
to a pacemaker.
What, if any, appliances should be avoided in a patient with
a pacemaker?
With modern pacemakers, no household appliances need to be
avoided.
- What is tachy-brady arrhythmia in the sick sinus syndrome?
- How can it be managed?
- In the sick sinus syndrome, patients develop episodes of sinus
bradycardia or sinus arrest and commonly, owing to diffuse atrial
disease, experience paroxysmal tachyarrhythmias. These together are
called the tachy-brady syndrome. - A permanent pacemaker (paces the two (Dual) chambers, senses
both D and reacts to both (DDD)) is required with antiarrhythmics to
control the tachycardia element.
Practically, how can we differentiate between a second-degree
atrioventricular (AV) block Mobitz I and Mobitz II? What is the meaning
of first-degree block? What is the difference between heart asystole, heart
arrest and third-degree AV block?
First-degree AV block (Fig. 13.2a)
This is prolongation of the PR interval to more than 0.22 s.
Second-degree AV block
● Type I, also called Mobitz type I or Wenckebach phenomenon (Fig.
13.2b): there is a progressive increase in the PR interval until a P wave
fails to conduct.
● Type II or Mobitz type II (Fig. 13.2c): some P waves do not conduct
to the ventricles and there is no progressive increase in the preceding
complexes of the PR interval as in Mobitz type I.
Third-degree AV block
Complete heart block occurs when there is complete failure of
conduction to the ventricles.
How can a complete atrioventricular (AV) block be diagnosed on an
electrocardiogram (ECG)?
The ECG shows complete dissociation between the P wave and QRS
complex
Usually, we look for an RSR pattern for bundle branch block in the chest
leads. What does it mean if there is an RSR pattern in the limb leads?
This usually indicates a right bundle branch block with either right
or left axis deviation, sometimes called a Wilson-type right bundle
branch block.
What is Wolff–Parkinson–White syndrome?
This describes patients with a history of palpitations in whom there
is conduction down an accessory pathway producing a ‘pre-excited’
electrocardiogram. There is a short PR interval followed by a slurred
initial part of the QRS complex known as the δ wave.
In one form the electrical impulse is conducted quickly over the
accessory pathway, thereby depolarizing the ventricle early, i.e. preexcitation,
with atrial activation via retrograde conduction through the
AV node.
In management of atrial fibrillation (AF), is the priority to control
ventricular rate or to restore cardiac rhythm?
There is greater emphasis at the present time in trying to control the
rhythm, if this can be achieved, because anticoagulation can be stopped
Can digoxin be given in paroxysmal atrial fibrillation?
Digoxin should not be used to prevent episodes of paroxysmal atrial
fibrillation. Digoxin can be used to slow the heart rate in a patient who is
in atrial fibrillation. The treatment of choice to prevent further attacks is
by catheter ablation of the arrhythmic focus.
In a patient with atrial fibrillation and bronchial asthma, what is
the recommended treatment and do beta-blockers make the condition
worse?
The treatment is either cardioversion (rhythm control) or AV nodal
slowing agents (rate control) but you need to carefully study the
management of this common condition. Beta-blockers should not be used
in patients with asthma; it makes the asthma worse
What is the difference between atrial flutter and atrial tachycardia?
Atrial flutter is an organized atrial rhythm at 250–350 beats per minute.
The most frequent is counterclockwise flutter, but re-entry flutter also
occurs. Atrial tachycardia is slower and is either a re-entry or automatic
tachycardia.
What are the possible causes of atrial extrasystoles, in a patient with
a normal echo, which last for several days and then disappear
spontaneously? Is treatment with anxiolytics recommended?
Atrial ectopic beats are usually of no significance. Treatment is not usually
required but a beta-blocker can be used, particularly with anxiety
In the treatment of ventricular tachycardia, could lidocaine be used in the
absence of any other drug? How effective is lidocaine?
Yes, lidocaine given as a bolus followed by intravenous infusion
(2–4 mg/min) is very effective. DC cardioversion is the other option.
Why is an extremely low level of potassium in the blood sometimes
a cause of ventricular fibrillation?
Hypokalaemia affects repolarization with progressively smaller T waves.
Usually, this has no immediate consequence but, particularly in the
presence of digoxin, ventricular fibrillation can occur
How often does verapamil cause impotence and inhibit ejaculation?
This is unclear. Most people think all hypotensive agents can produce
erectile dysfunction, but, in one study comparing a number of drugs only
thiazides caused more dysfunction than placebo
Why does a patient with congestive cardiac failure have excessive
sweating?
Excessive sweating is related to increased circulating sympathomimetics
such as epinephrine (adrenaline).
What is cardiac asthma?
Wheezing due to bronchial endothelial oedema occurs in cardiac failure
and is sometimes called ‘cardiac asthma’ to compare and contrast it with
bronchial asthma.
I wanted to ask whether a third heart sound is present, or should be
present, in all cases of heart failure, whatever the underlying cause.
Yes, it is present in left ventricular failure of whatever cause. The precise
mechanism of the cause of the third heart sound is not entirely clear. It is
associated with rapid ventricular filling.
Why can left heart failure lead to right heart failure but not vice versa?
What is the physiology involved in this transition?
Left heart failure is much more common than right heart failure and in
the backward pressure theory of heart failure right ventricular failure
develops as a consequence of left ventricular failure
Could you explain the fetal gene program, activated in heart failure?
Changes in the myocardial gene expression occur when the ventricle is
overloaded, i.e. heart failure and there is a return to the fetal pattern, as shown in animal models. There is a shift from αα (usually predominates
in the atrium) to ββ (usually mainly in the ventricles) myosin heavy
chains in the atria.
How safe is it to stop administration of carvedilol to a patient with
heart failure? Can the drug be tapered off? What are the effects/dangers of stopping carvedilol suddenly? What, if any, are the reasons for
discontinuing carvedilol in patients with heart failure?
There appear to be no dangers in stopping carvedilol suddenly or indeed
tapering off the drug. However, most patients should not have the drug
withdrawn, because of the good results reported with beta-blocker
usage. In one small study in patients who were taken off a beta-blocker,
deterioration or death occurred in 50% of a small group of patients.
Finally, bradycardia and poor cardiac output are the usual reasons for
discontinuing carvedilol and it is not appropriate to use it if a drug such
as milrinone is being considered
What are the advantages and disadvantages of furosemide in the
treatment of cardiac failure?
Furosemide promotes renal excretion of water and sodium, so relieving
fluid overload, i.e. oedema. It also has a venodilatory action, which is
why pulmonary oedema responds rapidly to IV furosemide. Its main
side-effect is hypokalaemia.
In heart failure, can furosemide be given once daily?
Yes; usually 40 mg in the morning is given, to avoid nocturnal urinary
frequency.
What are the clinical features of a ruptured sinus of Valsalva?
This usually occurs in a previously fit young man who suddenly has
shortness of breath and ischaemic chest pain. Heart failure is present
with a loud continuous murmur on auscultation. Echocardiography is
diagnostic. Treatment is urgent surgery.
Does dobutamine (dose range 2.5–10 μg/kg/min) cause significant tachycardia?
At this dosage there is an increase in myocardial contractility with little
effect on rate.
Are beta-blockers indicated in heart failure; if yes, in all cases or in
selected cases?
All patients with heart failure should receive a beta-blocker if there is no
contraindication, e.g. asthma, and if the drug is tolerated (in clinical trials
85% of patients tolerated beta-blockers). The initial dose should be low
to avoid initial side-effects, e.g. hypotension. In randomized controlled
trials, beta-blockers have been shown to improve symptoms as well as
reduce the risk of death and retard the progression of heart failure.
Why does long-term treatment by digitalis cause gynaecomastia?
Elevated plasma oestradiol levels (digoxin has intrinsic oestrogenic
properties) and decreased plasma testosterone levels occur
Why do toxic doses of digoxin (which cause a decrease in excitability of
cardiac tissue) cause arrhythmias, whereas therapeutic levels of digoxin
(which cause increase in excitability) cause no arrhythmias?
Toxic levels of digoxin cause an increase in intracellular calcium, which
leads to depolarization of the cells, initiating arrhythmia
Hypokalaemia is one of the complications of digitalis. In treatment
we give K
. How does the hyperkalaemia enhance the digitalis
toxicity?
Hypokalaemia is not a direct complication of digitalis therapy. Vomiting,
anorexia and diarrhoea are side-effects of digoxin therapy and can
contribute to hypokalaemia. Hyperkalaemia does not enhance digitalis
toxicity but too rapid a correction of hypokalaemia can lead to heart
block
Why should we measure serum potassium before we start digoxin?
Digoxin acts by inhibiting the Na
K
-ATPase pump. Hypokalaemia
increases the binding of digoxin to cardiac myocytes, potentiating its
action and decreasing its clearance as well as further inhibiting the
Na
K
-ATPase pump. Hypokalaemia should be corrected (it should
of course not be allowed to occur) in patients on digoxin. Paradoxically,
hyperkalaemia can occur in severe digoxin overdose, and might need
treatment with glucose and insulin.
The intravenous administration of loop diuretics such as furosemide
relieves pulmonary oedema rapidly. Is this due to arteriolar
vasodilatation reducing afterload which is an action that is independent
of its diuretic effect? I ask this because I have been told that this drug has
no effect on arterioles (except on efferent arterioles of the kidney), but
rather a venodilatatory effect. What could be the cause of such different
opinions?
Loop diuretics do primarily act on venules producing an acute increase
in systemic venous capacitance and thereby decreasing left ventricular
filling pressure. This effect is probably mediated by prostaglandins
released from the kidney. Some workers think that furosemide has an
effect on arterioles similar to morphine in pulmonary oedema
There have been a number of recent publications concerning aspirin
versus warfarin trials. Would you recommend prescribing warfarin for
secondary prevention of coronary heart disease in patients suffering from
their first myocardial infarction (MI)?
At the present time, aspirin is used routinely in all patients following
an MI unless there are contraindications. Warfarin is used if there is
evidence of a deep vein thrombosis (DVT), pulmonary embolism, mural
thrombosis on an echocardiogram, the presence of atrial fibrillation or a
previous embolic cardiovascular event.