ANGINA & HEART ATTACK (MYOCARDIAL INFARCTION)
Dr. Richard Mansfield
BSc (Hons) MB ChB MD FRCP FESC
CONSULTANT CARDIOLOGIST
Note: I am happy to answer general questions regarding the content of this website, but I cannot give clinical advice. Such requests will not be answered.
Wear and tear in the normal electrical wiring of the heart is more common with age. The normal pacemaker function of the heart can gradually wear out and is know as sinus node disease. Heart block occurs when the normal electrical activity in the heart cannot pass between the top (atria) and bottom chambers (ventricles). These situations may cause tiredness, fatigue or breathlessness. They may also result in dizzy spells or loss of consciousness (syncope). Treatment is often with a pacemaker.
Sinus tachycardia represents a normal increase in heart rate. This occurs when exercising, if nervous or with a fever. It may also happen if there is anaemia or a problem with the thyroid gland. It rarely requires treatment other than that directed at the underlying problem if there is one. Inappropriate sinus tachycardia is recognised in a small number of patients and may need specific treatment.
Supraventricular tachycardia (SVT) results from a disturbance in cardiac rhythm due to abnormal wiring in the normal electrical conduction system of the heart that causes a short circuit. Typically the heart rate changes suddenly and may result in chest discomfort, breathlessness or feeling light-headed. It usually stops as abruptly as it starts. Episodes may last from a few minutes to several hours.
There are two types of supra-ventricular tachycardia known as AV nodal re-entry tachycardia or AV re-entry tachycardia depending where the abnormal wiring is in the heart. Patients with SVT frequently require drug therapy and this would be discussed with the doctor. Medication may be taken when required ("pill in pocket") or may be required on a regular basis. Drugs for this include beta-blockers (Atenolol, Bisoprolol), Sotalol, Verapamil, Propafenone and Flecainide. If patients are still symptomatic despite one or two different types of medication, then onward referral for ablation therapy is commonly recommended.
Although similar to atrial fibrillation in many respects, atrial flutter results from a more organised abnormal electrical circuit in the small chambers at the top of the heart (atria). Whilst initially treated with tablets this is often effectively treated with ablation therapy.
This is a more serious form of palpitation most commonly linked to underlying heart disease but may otherwise occur in healthy people. It often leads to feelings of faintness or patients may pass out (syncope) and require immediate medical attention and resuscitation including defibrillation. It may therefore be life threatening and so needs prompt investigation and treatment. Treatment may be with tablets but many patients will have an implantable cardioverter defibrillator (ICD). This is a device similar to a pacemaker that can terminate the abnormal heart rhythm using an electrical shock if needed. Some patients with ventricular tachycardia will undergo ablation therapy.