Ischaemic Heart Disease.
Coronary Heart Disease.
Atheroma of the coronary arteries:
The commonest cause of changes in the luminal diameter of the
coronary arteries is the presence of atheromatous plaques.
The lesions may encircle an artery or may be eccentric ;they may
be discrete and localised or involve the greater length of the
vessel.
Acute changes in the plaques may account for unstable
angina,myocardial infarction and sudden death.,because
expansion of the lesion occurs when the endothelial cells
rupture,allowing haemorrhage into the plaque and platelet
aggregation on the endothelial surface.
Clinical feasture:
Symptoms:
The cardinal symptom is angina pectoris. This is a chest discomfort
precipited by exertion and relieved by rest. It is often descriped as
a pressing or constricting feeling.
The patient may hold a clenched fist in front of the sternum to
indicate the squeezing nature of the pain,and may describe
radiating discomfort in the left arm and jaw,or even a choking
sensation in the throat.
Dyspnoea frequently accompanies angina.
There is usually rapid relief of the symptom with sublingual
nitrate tablets.
The pain of myocardial infarction may be similar, but
generally begins at rest ,does not respond so well to nitrates,
lasts longer than 20 minutes and is often associated with
feeling of impending death,nausea,sweating and collapse.
Unfortunately, in many patients with I H D ,the first
manifestation of disease may be sudden death. Prevention of
atheroma is necessary to reduce this.
Signs :
There are few physical findings in uncomplicated I H D.
There may be evidence of hypertension or hyperlipidaemia
.
Cardiac dilatation,hypertrophy ,and failure are all late features and are
non-specific.
.Auscultation may reveals a fourth and third heart sounds over the apex
in Pt complicated with Lt vent .faliure.
Orthopnoea,and fine basal crackles are present in Pt developing
pulmonary oedema.
Some individuals have significant ischaemic episodes without
symptoms.This may discovered by routine ECG.
Other anginal syndromes
The previous is a desciption of typical angina.Several other anginal
syndromes occur which are less common.
1-Crescendo angina and unstable angina:
Both represent a state of preinfarction.In crescendo angina, a
history of increasingly frequent attacks of angina with ever-
diminishing levels of exertion is obtained.Unstable angina includes
situations where episodes of pain are frequent,may occure without
obvious cause and at rest.
Decubitus angina is angina occuring at rest in bed.
2-Vasospastic angina:
Some degree of arterial spasm is probably present in most
episodes of angina, but spasm on normal coronary can
occur(rarely),this spasm can be sever enough to cause
infarction.
In Prinzmetal’s syndrome,rest pain is associated with acute
ST segment elevation which resolves to normal with
cessation of pain.
This condition is rare and almost involves coronary
vasospasm.
Differential Diagnosis of Angina:
With all causes of chest pain:
1-Angina pectoris.
2-Angina due to Aortic valve stenosis.
3-Acute Myocardial infarction.
4-Aortic dissection.
5-Acute pericarditis.
6-Oesophageal spasm.
Chest Pain
1-Cardiac ischemic pain:
In a typical case the discomfort associated with myocardial
ischemia is described as a compression or tightness in the
chest which may also be felt in the throat, producing the
choking feeling being called angina pectoris.
Site:retrosternal.
Radiation:left side ,jaw ,arm,and forearm.
The precipitating causes are typically those which will increase
myocardial oxygen demand beyond the coronary .Excersion
,Emotional upsets ,Cold .
What increase:Emotions,stress,cold.
What decrease:Rest,Nitroglycerin GTN.
Duration:less than 10 minutes.
Special types of angina:Unstable angina it is more
sever form of angina,if untreated can lead to myocardial
infarction.
Myocardial infarction:
It causes pain similar to angina in site,radiation and character but it is
usually more sever and prolonged and persists despite taking glycerin
trinitrate.
Autonomic symptoms usually in association ,sweating
,irritability,palpitation ,nausea,and ,vomiting are common
,particularly in inferior wall infarction. Pt. may also be
breathless,restless with sensation of impending death.
With acute anterior infarction,tendency for sympathetic activity to
dominate,--tachycardia,cool pale periphery and normal or even
slightly high Bl.pressure in early minutes.This contrasts with acute
inferior infarction,which associated with massive vagal discharge
,producing a cold sweaty periphery,bradycardia,hypotension,nausea
and vomiting.
Painless or silent myocardial infarction is not
uncommon,particularly in diabetic patient and the elderly.
This patients may present later with complications from their
infarct such as cardiac faliure or an arrhythmia , diagnosis may be
made retrospectively from routine electrocardiogram (ECG).
Pericardial pain:
Chest pain is usually more localized than ischemic pain.
Site :retrosternal,may radiate to Lt shoulder.
Prodroma:may be preceded by viral illness.
Nature:stabbing and sharp.
Made worse by :change in posture,respiration.
Helped by :analgesics.,and NSAIDS.
Accompanied by :pericardial rub.
Aortic dissection:
The sudden development of a linear tear in the wall of the aorta is
called acute dissection.
The length of aorta affected varies from a few centimetres to the
whole vessel.
Site:retrosternal.
Onset:sudden.
Nature:very sever ,tearing pain.
Relived by:No ,tend to persist.
Accompanied by :Hypertension,Syncope.sweating,.
Risk factors for coronary Ht disease:
1-Age :increased in older age due to atherosclerosis.
2-Male sex .
3-Postive family history of IHD.
4-Hypertension.
5-Hyperlipidaemia.
6-Diabetes mellitus.
7-Obesity.
8-Lack of exercise.
Investigations:1-in angina:
1-Resting ECG:
Recording the electrical activity of the heart ,usually normal
in between attacks ,in attack it may show ST segment
depression,T wave inversion.
2-Excerise ECG :
It is recorded whilst the patient walks or run on motorized
treadmill or cycles.If there is +ve history of chest pain and –
ve resting ECG you can do stress ECG,it will be very useful
to confirm the diagnosis.
3-Cardiac scintigraphy:Or Nuclear imaging:
Myocardial perfusion scan at rest and with exercise,using
contrast like thallium,
(Th -201) is rapidly taken immediately after IV
injection,reflects the distribution of blood flow to the
myocardium--areas of decreased myocardial perfusion means
ischemia.(receive less thallium).
4-Echocardiography:Use echoes of ultrasound waves to map
the heart and study its functions.This can be used to assess
ventricular wall involvement..and vent.function,
Regional wall motion abnormalities at rest reflect previous
ventricular damage.
5-Coronary angiography:
This is occasionally usefull in Pt with chest pain and the diagnosis
is un clear.This can be done through cardiac catheterisation.
Coronary angiography is performed using catheters designed to
select Lt and Rt coronary artery,inject X- ray contrast
medium.,then the coronaries can be visualized.
it is usefull because it shows the exact coronary affected ,with
narrowing or obstruction .
Normal coronary angiography.
Coronary narrowing.
Treatement of angina:
1-Treatment of risk factors:
Hypertension ,DM,Obesity,stop smoking.Hyperlipidemia.
2-Medical treatement :
1- Vasodilators:Nitrates
.Glyceryl trinitrate(GTN)-tablets,and,skin patches.
Isosorbide dinitrate(oral,short acting+sustained release)
Isosorbide mononitrates-(oral some SR)
2- Beta blockers.
Atenolol(B1-selective)
Propranolol(non-selective.both tacken orally..
3- Calcium channel blockers.Nifedipin,Diltiazem,Verapamil.
3-Surgical :Coronary artery bypass grafting and angioplasty.
Treatment of unstable angin
1-ICU admission.
2-Bed rest and light sedation.
3-Oxygen.
4-Low dose aspirin.antiplatlet aggregator.
5-Heparin IV ,to minimise thrombus formation.
6-Nitrates (buccal or iv)
7-Close monitoring of blood pressure during nitrate infusion.care
about hypotension.
8-B-blockers and Ca antagonists may be added when needed.
In vasospastic or prinzmetal angina,the aim of treatment is to
prevent the powerful vasoconstriction:
Combination therapy using long acting isosorbide
mononitrate,+calcium antagonists.
Beta-blockers may have to be added to counteract the reflex
tachycardia and reduce the intensity of angina by reducing 02
demand during the attack.
Investigations in acute MI:
1-ECG: Q-wave ,and riased ST segment in affected leads.
2-Cardiac enzymes:
Creatinin kinase CK --CK-MB(cardiac specific).increased withen few
hours,and decreased in 24-48 hours.
Cardiac-specific troponins :Troponin I .,are regulatory proteins,increased in
cardiac injury.
Lactate dehydrogenase ( LDH):appers withen 12-24 hours,and disappered late.
3-A raised polymorphonuclear leucocyte count and elevated (ESR) are non specific
companiments of acute MI.
Treatment of acute MI:
Acute management:
Analgesia and oxygen,+bed rest.
.
If acute MI diagnosed ,Thrombolysis must be done with out delay .Six
hours is the time limit withen which it is possible that measures to restore
Bl.supply.
Thrombolytic treatement can achieve reperfusion in 50%-70% of
patients,and usually reduces the extent of ventricular damage and mortality
rate.
Streptokinase (1.5 million units over one hour) is the agent most
commonly used.
.
Asiprin ,as an antiplateletes,150 mg chewed.
Heparin.
Nitrates,by infusion early ,later on we can use skin patches.
B-blockers,-decreased the rate of cardiac deathes.
Follow up.
Complications of acute MI;
Acute complications:
1-Very early after infarction,all kinds of cardiac arrhythmia can
occur like:
Ventricular extrasystoles
Ventricular tachycardia
Ventricular fibrillation.
Atrial fibrillation.
Sinus tachy or bradycardia.
Conduction disturbance.
2-Cardiac failure.
3-Cardiogenic shock.
4-Thromboembolism ,due to Lt ventricular mural thrombus may
form on the endocardial surface of the infarcted region.
5-Acute ventricular septal rupture and ruptured papillary
muscle.Treatment is early surgery for both.
Late complications:
1-Pericarditis:can occure after MI as an early complication;occur days after
infarction,clinically: sharp chest pain aggrevated by movement.
2-Post myocardial infarction syndrome(Dressler syndrome):
Late complication:It is an autoimmune pericarditis ,(antibodies aginst
cardiac myocytes were detected) occur weaks or months after infarction
consists of pericarditis, fever,high ESR, and pericardial effusion.,treated
by NSAIDs,and corticosteroids.Prognosis is good.
3-Left ventricular aneurysm .