“Doctor, I had a Heart Attack Recently”
When a patient tells us this, the first thing that comes to our mind is to refer the patient back to his physician to get a clearance for the required dental procedure.
Many of the new dentists may not even feel confident while operating on such patients for the fear of the unknown complications.
Complications are the real enemy of any clinical practice. That doesn't mean that you should be avoiding such patients.
You should know the procedure (friend) you are performing well but at the same time you should know about the complications (enemy) and its management that may occur during that procedure.
So, let us get to know our common enemy in details.
Patients with a history of Unstable Angina or Myocardial Infarction usually undergo Angioplasty or Coronary Artery Bypass Graft (CABG) to re-establish blood supply to the area of infarction.
Following this, the patient is usually kept on Oral Antiplatelet (Aspirin) and/or Anticoagulant (Warfarin, Clopidogrel) therapy.
Anticoagulant therapy is to prevent clot formation inside the artery (Intra-Arterial Thrombosis).
In-depth discussion of Antiplatelet or Anticoagulant therapy is beyond the scope of this article. If you guys want me to write on this topic then let me know in the comment section or on my Facebook Page or Insta account.
Also, usually such patients have a history of Hypertension. So always measure Blood pressure and Heart rate before every procedure.
No dental procedure should be performed when diastolic pressure is over 100mm Hg and systolic pressure is above 180mm Hg. These patients are at a high risk of developing Angina pectoris or Myocardial Infarction.
Because of Anticoagulant Therapy and Hypertension, the patient is at a higher risk of hemorrhage, Intraoperatively and postoperatively.
Before any invasive procedure, always get the International Normalized Ratio (INR) of the patient measured.
Also, in such patients, Inferior Alveolar Nerve Block and Posterior Superior Alveolar Nerve Block should be avoided as they have the highest rate of positive aspiration. If a blood vessel is punctured while giving such blocks then it may lead to a huge hematoma which may cause airway blockade.
Instead, dental treatment should be done under local infiltration or Intra-ligamentary injection as much as possible.
When administering such a block is absolutely necessary, then advance the needle slowly and aspirate in two planes to ascertain whether you have punctured the blood vessel or not then deposit Local Anesthesia at a slow rate of 2ml/minute.
Also, always use a local anesthetic containing adrenaline. But try to use the minimum required dosage.
Many dentists avoid using Local Anesthesia with Adrenaline in a patient with any Cardio-Vascular Disease history.
You should remember that a limit of 0.04 mg per appointment is there for a reason.
If Adrenaline would’ve been contraindicated in a patient with Cardio-Vascular Disease then this Maximum Recommended Dosage for Adrenaline wouldn’t exist.
Rationale of using Exogenous (outside the body) Adrenaline is that it increases the duration and depth of Anesthesia.
If we don’t use Adrenaline with Local Anesthesia then the duration will be short and depth will be less of Anesthesia.
So, there is a high probability that the patient will experience pain during longer procedures.
When the patient experiences pain, psychological stress develops which causes a release of Endogenous (from inside the body) Adrenaline.
And this endogenous adrenaline is approximately 250 times more than the exogenous adrenaline that we would’ve injected with Local Anesthesia.
This endogenous Adrenaline will lead to peripheral vasoconstriction. This increases blood pressure which increases work load on Myocardium.
There is also vasoconstriction in coronary arteries. There is Increased oxygen demand and reduced supply.
So, Not using Adrenaline in Local Anesthesia increases the chances of Angina Pectoris or Myocardial Infarction.
Also, you should never use gingival retraction cords soaked with Adrenaline.
Absorption from the gingival sulcus is rapid. This will lead to a rapid rise in Adrenaline levels in the blood leading to peripheral vasoconstriction and hence, Angina Pectoris or Myocardial Infarction.
Of course, Adrenaline is contraindicated in a patient with Ventricular Fibrillation, Dysrhythmia or a patient on Non-selective Beta Blockers (Propranolol).
Another thing you need to remember is that there is tissue death in myocardium because of obstructed blood supply in Myocardial Infarction.
So, no dental procedure should be performed within 6 months of the last Myocardial Infarction.
All the cases should be managed medically (Antibiotics and Analgesics).
Reason for this is that, as the blood supply to a region is hampered because of Myocardial Infarction, our body tries to establish a new (collateral) blood supply to that region. And it takes approx. 6 months to do that.
If any dental procedure is performed within 6 months of Myocardial Infarction, there is a high probability of another Myocardial Infarction to occur because of the psychological stress.
Angina Pain Mistaken as Dental Pain
It should also be remembered that Ischemic Heart Disease pain, although rare, can be felt as pain in mandible.
Such a referred pain of cardiac origin can lead to a diagnostic dilemma for the clinicians.
An improper diagnosis can result in unnecessary dental treatment and more significantly, it can delay the proper treatment of the cardiac problem and that may lead to myocardial infarction.
Differentiating the site of pain from the source of pain is important so that the treatment will be properly directed towards the source of pain.
Discontinue Anticoagulant Therapy ???
A dentist is usually in a dilemma about whether to discontinue anticoagulant therapy or not.
As far as my experience goes, in a patient with an International Normalized Ratio (INR) of ≤3, bleeding is manageable after an atraumatic dental extraction, using Gel foam, sutures and pressure application with a Tranexamic acid-soaked gauze. Optionally, two doses of Tab. Ethamsylate 500 mg can be given 8 hours apart.
Surely a Root Canal Treatment or other non-surgical dental procedure can be performed without any major bleeding complication.
The rationale of not discontinuing the anticoagulant therapy is that the risk of bleeding is far smaller than the risk of life-threatening thrombosis that we are putting the patient at by stopping the anticoagulant medications.
Do not use Adrenaline soaked gauze to control bleeding.
Adrenaline initially causes vasoconstriction but after a few hours it causes vasodilation. This would lead to secondary bleeding.
If there is recurrent bleeding after minor surgical procedures like dental extraction or you are not able to control the bleeding, then you may have to consult the treating physician of the patient.
Usually the physician controls the bleeding using Intravenous Antifibrinolytic Agents such as Tranexamic acid, Aminocaproic Acid, Ethamsylate or a combination of these drugs.
If the patient is to undergo extensive surgery, be it minor or major, anticoagulant therapy should be discontinued after consultation with the patient’s treating physician.
The anticoagulant therapy is usually discontinued minimum 3 days prior to the dental procedure.
I would suggest discontinuing anticoagulant therapy with physician consultation, for any dental surgeon who is not confident in managing excess bleeding even in a normal patient.
Usually such patient has a history of Hypertension also.
So, we have to keep an eye on drug induced dental problems.
Calcium Channel Blockers (Amlodipine) cause Gingival Hyperplasia.
Majority of Antihypertensive drugs cause some degree of Xerostomia and altered taste sensation.
These are the things that you need to keep in mind while treating a patient with Ischemic Heart Disease.
I hope this post will help you manage such medically compromised patients confidentally.
In the next post, I will be talking about management of Angina and Myocardial Infarction emergency that may occur at a dental office.
Do let me know what topics would you want me to write about next. The topics can be from local anesthesia, Oral & Maxillofacial Surgery or Medical emergencies.