Cardiovascular diseases: From rich man's disease to common man's disease.
Cardiovascular diseases (CVD), once perceived primarily as a rich man's disease has now become the major disease of all economic groups rich or poor. A quarter of all mortality in India is attributed to CVD as per World Bank associated report (https://www.dcp-3.org/resources/global-burden-cardiovascular-disease-india-current-epidemiology-and-future-directions ).
In India, the epidemiological transition from predominantly infectious disease condition to noncommunicable diseases has occurred over a brief period of time. It has accelerated during 1990s and became a permanent fixture in 2000s coinciding with the broader socio economic transformation in India.
During transition, the general public in India abandoned physically demanding occupations (preferred 9 to 5 sedentary occupations), increased the calorie intake (due to economic and social advancement), a high incidence of smoking and increased the consumption of processed food and alcohol (perceived as a status symbol), reduced walking (preference for motorized vehicle).
Once the domain of the wealthy, these lifestyles combined with modern stressors like job insecurity, long working hours, social isolation & disrupted sleep have increased the risk of cardiovascular diseases among Indians across all age groups.
https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.114.008729 - American Heart Association Journals
Anatomy of heart:
A fist sized muscular organ, heart. is the main organ in our cardiovascular system that pumps blood throughout our body. It is made up of muscles and tissues. It constantly sends oxygen to our cells and takes away waste. It controls the rhythm and speed of our heart rate and also maintains blood pressure.
Our heart is in front of our chest. It sits slightly behind and to the left of our sternum (breast bone) which is in the middle of our chest. It sits between our left and right lungs. The left lung is slightly smaller to make room for the heart in our left chest. Our rib cage protects our heart
Our heart has four separate chambers, two on the top (left and right atrium) and two on the bottom (left and right ventricles). Two large veins deliver oxygen - poor blood to the right atrium. The superior vena cava carries blood from the upper body whereas the inferior vena cava carries blood from the lower body. Then the right atrium pumps blood to the right ventricle. The right ventricle pumps the oxygen - poor blood to the lungs through the pulmonary artery. After the lungs fill the blood with oxygen, the pulmonary vein carries the blood to the left atrium. The left atrium pumps the blood to the left ventricle. The left ventricle pumps oxygen - rich blood to the rest of our body through aorta. The left ventricle is slightly larger than the right.
Heart electrical conduction system
https://my.clevelandclinic.org/health/body/21648-heart-conduction-system - Heart conduction system
Our cardiac conduction system is the network of nodes (groups of cells that can be either nerve or muscle tissue), specialized cells and electrical signals that control our heartbeat. Each time our heart beats, electrical signals travel through our heart. These signals cause different parts of our heart to expand and contract. These actions regulate blood flow through our heart and body.
Heart's conduction system's specialized cells and nodes are:
Sinoatrial node (SA node is our heart's natural pace maker) is in the upper part of our heart's right atrium.
Atrioventricular node (AV node), located near the central area of our heart
Bundle of His (atrioventricular bundle) is a branch of fibers (nerve cells) that extends from AV node. This fiber bundle receives the electrical signal from the AV node and carries it to Purkinje fibers. Bundle of His is named after Wilhelm His Jr., the Swiss cardiologist who discovered and described this part of the heart.
Purkinje fibers are branches of specialized nerve cells which send electrical signals very quickly to the heart's right and left ventricles. Purkinje fibers are named after the Czech anatomist Jan Evangelista Purkyne.
Heart blood flow:
Heart receives nutrients through a network of coronary arteries. These arteries run along the surface of the heart . There are
Left coronary artery divides into two branches, left anterior descending artery (LAD) and the circumflex artery (Cx)
Left anterior descending artery (LAD) supplies blood to the front and bottom of the left ventricle and the front of the septum
Circumflex artery (Cx) supplies blood to the left atrium and the side and back of the left ventricle
Right coronary artery (RCA) supplies blood to the right atrium, right ventricle, bottom portion of the left ventricle and back of the septum.
Heart diseases / Coronary artery disease (CAD):
There are number of types of heart disease with multiple causes. Of them, coronary artery disease (CAD) is the most common and familiar type. CAD is the main focus of this blog as well.
As per WHO 2021statistics, heart diseases is the leading cause of death (India is no exception) and is responsible for 13% of world's total death.
Cardiac ischemia is a decreased blood flow and oxygen to the heart muscles. Ischemic heart disease is heart damage caused by narrowed heart arteries. This is also called coronary artery disease (CAD). When arteries narrow, less blood and oxygen reach the heart muscles. This can lead to heart attack.
Narrowing of coronary arteries is caused by gradual buildup of plaque,which contains cholesterol, fatty material, inflammatory cells and other materials. Over the years, it can enlarge and reduce the space available for blood blow. The traditional risk factors for CAD are high LDL cholesterol, low HDL cholesterol, high blood pressure, family history, diabetes, smoking and obesity (credit: heart.org)
Ischemia can cause angina, which develops chest pain, discomfort in arms or lower jaw. Angina typically develops during physical exertion or emotional stress. Angina usually lasts several minutes and goes away with rest.
Persons with coronary atherosclerosis (slow buildup of sticky plaque inside the arteries) are at risk for suffering a heart attack A heart attack can occur when a coronary artery becomes blocked, usually by a blood clot. The region of the heart muscle fed by the blocked artery loses its ability to function and eventually turns into a scar tissue. Unlike anginal pain, a pain from a heart attack usually lasts more than 20 minutes and does not go away with rest.
Some heart attacks are sudden and intense without any warning. Others start slowly with chest discomfort in the center of the chest. It can last more than a few minutes, or it may go away and then return. It can feel like uncomfortable pressure, squeezing, fullness or pain. Discomfort in the areas of upper body, arms (one or both), back, neck, jaw, and stomach. Shortness of breath and breaking out in a cold sweat, nausea, rapid or irregular heartbeat, feeling unusually tired & lightheaded. Symptoms vary between men and women.
Apart from the common heart attack symptom chest pain (angina) or discomfort, women have other symptoms like anxiety, nausea, vomiting, upset stomach. If you see someone suffering from any of the above warning signals, call emergency ambulance service (108 for Pan India and 911 for USA & Canada) and take them to the nearest hospital.
Golden hour is the first 60 minutes right after the heart attack starts. Getting medical help during this window is vital that gives the patient the highest chance of survival and prevents permanent heart damage. In the first 0 to 60 minutes the heart muscle is struggling but can be saved if the blood flow restarts. Chewing an Aspirin tablet (if advised and not allergic) can help stop platelets from adding to the clot.
Heart attack is different from cardiac arrest, but common people use these terms to mean the same thing, but they are different events. Heart attack is a circulation problem when blood flow to the heart is blocked. Sudden cardiac arrest is an electrical problem caused by irregular heart rhythms. With sudden cardiac arrest, the heart malfunctions and suddenly stops beating. A common and potentially deadly cardiac arrest is ventricular fibrillation. This happens when the heart's lower chambers start beating chaotically and don't pump blood. Cardiac arrest may be reversed if both CPR (cardiopulmonary resuscitation) and a defibrillator is used within minutes to shock the heart and restore the normal heart rhythm.
Cardiovascular disease is not confined to the heart. The same vascular disease factors that damage coronary arteries can also damage blood vessels supplying the brain. Stroke (cerebrovascular accident) is an ischemic stroke or 'brain attack' is a sudden loss of brain function resulting from a disruption of the blood supply to a part of the brain. There are two types of strokes. Ischemic stroke, blood clots that plugs or blocks a blood vessel to the brain, Hemorrhagic stroke caused by a blood vessel that breaks and bleeds into the brain https://medlineplus.gov/stroke.html
Different types of treatment for coronary artery disease (CAD)
Qualified physicians analyze the medical history of the patient and perform complete physical examination including Electrocardiogram (ECG) and tread mill stress test to decide the course of action based on the medical conditions of the patient and the warning signals (severity of chest pain. pain and discomfort in other parts of the body) in line with the approved international guidelines. This guideline suggests exactly when to perform angiogram, angioplasty (stenting) or bypass surgery.
The optimum method of diagnosing CAD is by coronary angiography. This test is performed under local anesthesia and involves injecting x-ray dye (contrast medium) into the coronary arteries via tubes (catheters) while an x-ray camera makes a film of the blood flow pattern that shows the exact location and severity of the coronary artery narrowing.
The findings from the angiography guide the strategy for the best treatment. The options for medical therapy, angioplasty (stenting) or coronary artery pass surgery depend largely on the severity of the disease. In general, patients with coronary artery narrowing that do not limit coronary artery blood flow receive medications and lifestyle modification to help prevent progression.
If a patient has coronary atherosclerosis (slow buildup of sticky plaque inside the arteries) that limits blood flow inside the coronary arteries, balloon angioplasty and stenting can be offered. The sequence of carrying out balloon angioplasty and stenting is explained in the diagrams below.
In patients with multiple areas of coronary artery narrowing or blockage, coronary artery bypass graft surgery is generally recommended. Also, the most important artery, the left anterior descending artery (LAD) which feeds blood to whole front wall of the heart has narrowing or blockage, then bypass is usually a best choice (Harvard)
Sequence of coronary bypass graft surgery is explained below.
https://www.ahajournals.org/doi/10.1161/01.cir.0000044747.37349.64 - American Heart Association (AHA) Journal
The minimally invasive direct coronary artery bypass (MIDCAB) technique is a less invasive version of the traditional CABG. In this, the surgeon makes a small incision between the ribs to operate on the blocked artery. This technique generally cannot be used when there are more than two blocked arteries, usually involves shorter hospital stay and recovery period.
The decision to go for coronary artery bypass graft is always emotional, financially and psychologically demanding for the patient and for his/her family. Many doctors and international organizations such American Heart Association (AHA) recommend having a second opinion before consenting to have a coronary artery bypass surgery. Second opinion may make the patient to feel confident, to reduce the risk of the bias of the health care professional, to get the less expensive medically viable option and sometimes to meet the insurance companies' requirement. In Chennai, a voluntary group named 'medical assistance 24 x7', headed by Dr. R. Senthil Kumar is helping patients to get second opinion from the leading doctors in Chennai, free of charge. His official contact number is +91 8110004517.
Tamil Nadu Government's 'இதயம் காப்போம்' - 'Idhayam Kaapom' (Heart attack management program) protocol advises health care workers in the Health Sub-centers (HSCs) and Primary Health Centers to administer loading doses (Aspirin 300mg, Clopidogrel 300mg, and Atorvastatin 80mg) the moment the heart attack is provisionally identified before transporting the patient to a larger cardiac facility
Prevention strategies:
One's lifestyle is the best defense against heart disease. The following steps can help reduce some
risk factors for heart disease, heart attack and stroke.
A healthy diet is one of the best weapons to fight heart disease.
A heart - healthy eating plan includes vegetables & fruits, beans of other legumes, lean meat, fish, whole grains, low fat or fat free dairy foods. Reduce the intake of salt and high-sodium meals, sugar & sweetened beverages, highly processed foods, saturated fat foods and trans fat foods such as fried fast foods, chips and baked goods.
Be physically active
Regular, daily physical activity can lower the risk of heart disease. In general, one can aim at least 150 minutes a week a moderate aerobic activity, such as walking at brisk pace or 75 minutes a week of vigorous aerobic activity, such as running, plus two or more strength training sessions a week
Aim for a healthy weight:
Being overweight - especially around the middle of the body- raises the risk of heart disease. A Body Mass Index (BMI) of 25 or higher is generally considered as overweight. Waist circumference can also be a useful tool to measure how much belly fat one has. The risk of heart disease is higher if the waist measurement is greater than 40 inches for men and 33.5 inches for women. Reducing weight by just 3% to 5% can help lower certain fats in the blood called triglycerides, It can lower blood sugar and can cut the risk of type 2 diabetes.
Lower high blood cholesterol
Reduce the intake of saturated fat and avoid trans-fat. A low-density lipoprotein (LDL) cholesterol less than 70mg/dl is considered good for one's heart health. High levels of High - Density lipoprotein (HDL) are typically better. An optimal level of 60 mg/dl or higher is recommended. Heath care professionals may recommend lifestyle changes to lower the LDL and increase the HDL
Lower high blood pressure
The optimum blood pressure level is less than 120/80 mm Hg. High blood pressure is a majoe risk factor for stroke. Reduce the salt intake to keep the blood pressure within optimal level
Manage diabetes
Diabetes is a lifelong condition. Even when blood glucose levels are kept under control, diabetes greatly increases heart attack and stroke risk. If one has diabetes, regular medical checkups are critical to keep blood sugar under control.
Get enough sleep
Getting a good night's sleep every night is vital for the heart's health. The amount and quality of sleep can affect eating habits. mood, memory, internal organs and more. Adults shouls aim for an average of 7 to 9 hours a night. We can improve the quality of sleep by being physically active during the day, creating a bedtime routine and keeping the electronic devices out of the bedroom.
Reduce stress
Stress can lead to unhealthy habits including smoking, overeating and not being physically active. Chronic stress may lead to high blood pressure. These factors can increase the risk for heart disease and stroke. To manage the strees, exercise regularly, making time for friends and family, and practice relaxation techniques.
Stop smoking
Chemicals in the tobacco can damage the heart and blood vessels. Cigarette smoke lowers the levels of oxygen in the blood, which raises the blood pressure and heart rate. That's because the heart has to work harder to supply enough oxygen to the body and brain.
Limit alcohol
Drinking too much alcohol can raise blood pressure, increase cardiomyopathy, stroke and other diseases. It will contribute to high triglycerides, cause irregular heartbeats and contribute to obesity, alcoholism. If you drink, limit the drink to one drink per day. The National institute of Alcohol abuse and alcoholism defines one drink as 1-1/2 fluid ounces of 80 - proof spirits such as bourbon, Scottish, vodka and gin, 5 fluid ounces of wine and 12 fluid ounces of regular beer.
7.Medical terms:
Ischemic: A condition where a part of the body receives deficient blood supply due to narrowed or blocked blood vessels (Webster dictionary)
Vascular: Relating to the vessels that carry blood or other liquids in a person's or animal's body (Cambridge dictionary)
Cerebrovascular: Relating to the blood vessels (arteries and veins) supplying the brain (Cleveland clinic)
Hemorrhage: A large flow of blood from the damaged blood vessel (Cambridge dictionary)
Septum: A dividing wall or membrane especially between bodily spaces or masses of soft tissues (Webster dictionary) - In heart, interventricular septum separates the right ventricle from the left ventricle. Similarly, inter atrial septum separates the right atria from the left atria
Atherosclerosis: Slow buildup of sticky plaque inside the arteries
CABG: Coronary artery bypass graft
Cardiomyopathy: A disease of a heart muscle to make it harder for the heart to pump blood to the rest of the body.
Disclaimer:
The content provided in this blog is for information and education purpose only. It is not intended to be a substitute for professional medical advice.
Fine. Clear Explanations about Heart attack, Cardiac arrest, Stroke etc as well as preventive suggestions.
Shows your vast knowledge in medical field also. Congratulations.