Stress and heart disease

How does stress cause heart disease?

Stress and heart disease has various aspects. Stress can lead to increase in risk factors for heart disease as well as precipitate symptoms in a hitherto silent heart disease. Most older persons have build up of plaques in the blood vessels of the heart (coronary arteries). When there is a sudden severe stress, heart rate and blood pressure can shoot up. This can lead to increase of shear stress on the fat plaques in the blood vessels of the heart. A small break may form in the covering of the plaque, exposing the inner cells. Blood components known as platelets adhere to these breaks in the inner surface of the blood vessels and initiate the formation of blood clots. Blood clots in turn block the flow of blood in the vessel, leading to damage of heart muscle known as heart attack.

Sudden stress can sometimes lead to a surge in the blood levels of certain hormones like adrenaline. These contribute to the surges in blood pressure and heart rate. In addition this can upset the heart rhythm leading to life threatening rhythm disorders (cardiac arrhythmia) which can sometimes cause sudden stoppage of the heart (cardiac arrest).

Another manifestation of stress in the heart is the ‘broken heart syndrome’ or stress cardiomyopathy. This was initially described more in elderly females after sudden demise of their spouse. Part of the left ventricle (lower muscular chamber of the heart) becomes enlarged, giving it the name apical ballooning. This occurs in the absence of any blockage to the blood supply. Most of these cases do recover sooner or later. Stress cardiomyopathy has been described along with multiple other forms of stress other than bereavement.

Stress in general changes our life style and we may eat more of carbohydrate and fat. This has long term consequences like increase in body weight, blood sugar and blood pressure. These can further increase the chance of heart disease. Stress increases the blood pressure and blood sugar through hormonal influences even without a change in the diet pattern.

Compression only CPR

What is CPR?

CPR stands for cardiopulmonary resuscitation given for victims of cardiac arrest. It has two components – chest compression to replace the pump function of the heart and artificial breaths – mouth to mouth or mouth to nose breaths or using a device known as Ambu bag. Ambu bags though available with rescue teams, is not available to lay rescuers on the spot. Hence many potential lay rescuers may hesitate to start CPR, being afraid of transmission of infection from the unknown victim. This hesitation can be avoided by compression only CPR.

What is compression only CPR?

Compression only CPR is usually meant for lay rescuers, in which chest compressions are provided till an AED (automatic external defibrillator) is available or emergency medical service arrives on scene. By providing chest compressions, circulation is achieved, to give enough blood with oxygen to the brain to maintain its viability for a short period. It has been shown to be much superior to lack of CPR and nearing the efficacy of conventional CPR if the duration needed is short. This is because blood in the heart contains sufficient oxygen at the time of most cardiac arrests in adults. This is not the case in drowning and most cardiac arrests in children, where artificial breathing is needed from the beginning.

How useful is compression only CPR?

Efficacy of compression only CPR performed by lay rescuers in adult victims is comparable to conventional CPR performed by them as per recent studies. In children conventional CPR is better. But if the lay rescuer is unwilling to perform conventional CPR (chest compression with rescue breaths), they may perform compression only CPR as it is definitely better than no CPR. Initiation of any form of CPR is associated with a better prospect of survival for the victim.

Cardiac arrest

What is cardiac arrest?

Cardiac arrest is nothing but sudden stoppage of the functioning of the heart. It is different from heart attack which is abrupt loss of blood supply to a region of the heart muscle. Heart attack can lead to cardiac arrest in some of the victims. Though both are medical emergencies, cardiac arrest is equivalent to death unless immediate measures are taken to swing heart back into action. This is usually done by chest compressions and artificial breathing (cardiopulmonary resuscitation or CPR – Basic life support or BLS), to be soon followed by electrical countershock (defibrillation) delivered by a device known as defibrillator, to correct the abnormal rhythm of the heart which caused the cardiac arrest.

How soon should CPR be started?

CPR should be started as soon as possible. The time window for successful CPR is very narrow. Irreversible brain damage can occur if blood circulation stops more than 4 minutes as the brain is very much dependent on oxygen supplied by the blood. Even with CPR, it is difficult to maintain good blood circulation to the brain to sustain it for a long period. Usually CPR provides only about one fourth of the normal blood supply. Hence the time window available to us is about 12 minutes with CPR, unless advanced cardiac life support (ACLS) is available.

What is AED?

AED is short for automatic external defibrillator. AED is an electronic device being deployed more and more in public places to treat victims of cardiac arrest. It is also known as public access defibrillation. AED has two electrode patches which can be applied to the chest. It will sense the cardiac rhythm and interpret it using a built in computer algorithm. If a rhythm which can be shocked back to normal (ventricular fibrillation or tachycardia – fast rhythms of the heart) are detected, the devices prompts a shock delivery. Everyone should clear off the victim when the shock is being delivered. If it is not a shockable rhythm, the device gives audio prompts to continue CPR.

What is ROSC?

ROSC is the acronym for return of spontaneous circulation. Once ROSC is achieved, further care is known as post resucitation care or post cardiac arrest care. This is aimed at minimizing the brain injury caused by the period of lack of oxygen supply to the brain during cardiac arrest.

Heart attack

What is heart attack?

Heart attack (Myocardial Infarction) is damage to a region of the heart muscle, usually due to sudden blockage of a blood vessel supplying oxygenated blood to the region (coronary artery). Though heart attack can occur due to a mismatch between the supply and demand for blood in the region, the usual heart attack which we are familiar with is due to blockage of a blood vessel. Heart attack is different from cardiac arrest. In cardiac arrest, heart stops beating and it is equivalent to death unless the function of the heart is promptly restored either spontaneously or by chest compression and artificial breathing protocol known as cardiopulmonary resuscitation (CPR).

What are the important symptoms of heart attack?

The most familiar symptom of heart attack is severe central chest pain. It is often associated with sweating, fatigue, dizziness and sometimes breathlessness. Rarely there are no symptoms and then it is known as a ‘silent heart attack’. Some unfortunate victims of heart attack develop a cardiac arrest and may die suddenly (sudden death). Sudden death in heart attack is often due to a sudden change in the heart rhythm which makes the heart stand still (ventricular fibrillation). This abnormal rhythm can be treated by CPR and direct current shock using a device known as defibrillator which shocks the heart back into action. An automatic external defibrillator for use of untrained persons, is now available in many public places like airport.

What to do if you think you are having a heart attack?

First and foremost is to take rest and call for emergency support. In regions where an emergency ambulance service is available, it should be called and one should proceed to the nearest hospital. In well equipped ambulances, it is possible to make a diagnosis and start early treatment even before reaching the hospital. After initial assessment by the paramedic, an electrocardiogram (ECG) is recorded. When facility is available, the ECG is transmitted to the receiving hospital where the team is ready for further action even before arrival of the victim.

It is not advisable to travel in a self driven vehicle to the hospital unless you have no other options. This is because occasionally cardiac arrest can occur en route. Moreover arrival in ambulance speeds up management in the emergency department. Traffic worries are also lesser while travelling in an ambulance. This is in addition to the medical support available in the ambulance.