Smoking has a detrimental impact on coronary health, it can cause conditions such as heart attacks, coronary heart disease, and heart failure. Atherosclerosis formation inside the arteries which will consequently increase blood pressure and heart rate. All this puts so much tension on the cardiovascular system. In this article we will be discussing all of those aspects of how smoking can affect coronary heart health and ways to protect it from occurring.    

Introduction 

The phrase “heart disease” is numerously used to refer to a variety of disorders that impact the function of the heart. When a person has coronary heart disease, their heart's arteries are unable to supply oxygen-rich blood to their heart muscle. This is due to the build up of a waxy layer of cholesterol inside the lining of the arteries which will cause partial or total blockage of blood flow in the larger arteries of the heart.¹ The main role of the coronary arteries is to supply the myocardium with blood and oxygen to allow contraction of the heart and consequently the circulation of blood all around the human body. ² Because friendly troops were given free cigarettes as a morale boost during the First and Second World Wars, smoking frequency surged dramatically at that time. Smoking rampancy declined during the early 20th century owing to the increased knowledge amongst individuals about the health effects of smoking.

The chemicals found in tobacco smoke can be extremely harmful to smokers and nonsmokers as well. Inhaling even little tobacco smoke could lead to serious health issues which are considered very dangerous. Tobacco contains more than 7,000 chemicals and out of those, at least 250 are considered to be very detrimental which are nicotine, tar, carbon monoxide (CO), hydrogen cyanide and ammonia. 69 out of 250 are known to be cancerous, which include, aromatic amines, benzene, and acetaldehyde.³   

The impact of smoking on coronary arteries 

• Formation of plaque (Atherosclerosis)

Plaque will build up inside the coronary arteries (atherosclerosis), therefore, reducing the flow of blood to the heart and heightening the risk of heart attack due to blockages and constriction of the coronary arteries.⁴

•  Damage to the endothelium 

The endothelial cells construct a single cell layer that lines all the blood vessels and modulate the interchange between the tissues surrounding the cell and bloodstream. ⁵ The endothelial cells are known to be a huge contributor to the control of fluidity in blood, vascular tone,  aggregation of the platelets, inflammation and angiogenesis, and immunological regulation.⁶ 

Smoking can cause endothelial dysfunction which will give rise to oxidative stress and vascular inflammation, this is linked to the release of cytokines, adhesion of the inflammatory cells and consequently, leading to disarrangement of the protective layer of the endothelium.⁷

• Reduced oxygen supply

Due to the quick diffusion of CO across the pulmonary capillary membrane, it will bind to haemoglobin in a faster pace and affinity than oxygen, leading to the formation of carboxyhemoglobin, hence reducing oxygen supply to the surrounding tissues. This will, therefore, lead to insufficiant supply of oxygen to the heart muscle causing coronary heart disease, myocardial infarction (heart attack), and heart failure.⁸

Smoking and increased risk of heart attack

• Role of blood clots

Heart attacks can be caused by thrombosis, which is a critical condition where blood clots can form in your heart and/or blood vessels. Consequently, the blood flow will be restricted from the area the blood clot is formed at or it can travel elsewhere in the body. If the blood clot is thrust in a critical area, life-threatening events will take place like heart attacks and strokes.⁹

Tobacco, tar, nicotine and other chemicals in cigarettes can significantly increase the chances of blood clots being formed. This is due to alliteration of the blood platelet surface making it easier for them to clump together (sticky blood). The blood vessel lining damage is also linked to smoking which increases the likelihood of blood clots being formed.¹⁰ Smoking can also lower HDL cholesterol levels and raise the risk of plaque development in blood arteries. 

• Increased heart rate and blood pressure

Nicotine found in cigarettes can stimulate the sympathetic nervous system (SNS) which will release noradrenaline and, in return, this will cause an increase in blood pressure and heart rate (tachicardia), enhancing heart contractility, and construction of blood vessels (vasoconstriction).¹¹ Nevertheless, long-term effects of nicotine on coronary heart health could be detrimental, because nicotine is an addictive substnace which will elevate atherosclerosis formation, coronary artery disease, increase blood pressure and may cause heart attacks.¹² 

Smoking and coronary heart disease 

• Statistics and Risk Factors

According to the world health organisation, more than 500,000 people in the United States die because of cardiovascular diseases and 10% of them are caused by second hand smoking.¹³ Tobacco intake is one of the dominant causes of death in the U.S. and leads to 440,000 deaths every year.¹ One in every five reported cases of smoking deaths is caused by heart attack. Women above 35 who smoke and take birth control pills are at a higher risk of stroke and heart diseases.¹⁴ Smokers are more likely to get Coronary Heart Disease than nonsmokers by 2 to 4 times. Also there are impacts on Nonsmokers who are exposed to secondhand smoke or passive smoking who can end up getting a heart disease.¹⁵ Coronary artery disease is considered to be the main cause of morbidity and mortality in the United states and worldwide.¹

Benefits of quitting smoking

After quitting smoking your blood pressure will be much more stabilised and the heart rate will slow down as well. The oxygen will start to reach your heart in a much higher affinity due to the decrease in carbon monoxide concentration in blood and the bloodstream will be nicotine-free. This all can be achieved only after 1 day of quitting smoking. After 2-5 years of quitting smoke, your risk of having a heart disease will be significantly reduced. After 20+ years your chances of getting a heart attack will resemble someone who has never smoked before.¹⁶

Strategies for quitting smoking

• Nicotine replacement therapy: to provide a controlled release of nicotine to help with the withdrawal symptoms. There are a variety of forms in NRT which includes, gums, lozenges, patches, inhalers, and nasal spray 
• Behavioural therapy and counselling: to recognise the triggers of smoking. There are many types of behavioural support, which include Cognitive behavioural therapy, individual and group counselling, online support programs, and relaxation techniques    
• Prescription medication: to reduce craving level and withdrawal symptoms.¹⁷ 

FAQ’s

What is coronary artery disease?

CAD is the blockage or narrowing of the coronary arteries that supply oxygenated blood to the heart due to the build up of a waxy layer of cholesterol known as atherosclerosis.¹

How can smoking cause coronary artery disease?

The chemicals found in cigarettes like carbon monoxide and nicotine will cause an increase in blood pressure, heart rate and inflammation. After smoking for a long period of time, plaque will further build up and narrow the arteries which will stop the blood flowing to heart which will cause life-threatening issues such as CAD.⁴ 

Summary   

Nevertheless, smoking can cause life-threatening events like coronary artery disease, heart attacks, and heart failure. Major effects include atherosclerosis, high blood pressure and heart rate, oxidative stress, and inflammation. Quitting smoking can significantly reduce those threatening events because it will decrease the chances of having heart-related issues and will ameliorate coronary health.