Sudden Death
PKGhatak, MD
In human experience, an unexpected sudden death must be the most devastating and sad event for the family members.
When death finally comes to a person with an incurable chronic illness, some may say “Good is merciful and he/she is in peace. But what one can say to a mother when a child is killed in a school by gunshot or a newborn die from sudden infant death syndrome. Is the same God merciful here also?
In the USA about 200,000 deaths are happening every year from unintentional causes, chief among them are drug overdose, motor vehicle accidents, fall, and drowning. Deaths from gun violence and suicide are 45,000 per year for each. The remaining deaths are from accidents. heart attacks and undetermined causes. The deaths from undetermined causes, pose another dimension to the suffering for the family – did they miss something to spot in time and take proper action to prevent death.
Sudden Infant Death Syndrome.
Healthy infants below 1 yr. old were dying suddenly for no apparent reason. This was a major concern of health professionals and in 1969 'Sudden Infant Deaths Syndrome (SIDS)' was coined in order to study these cases and find the cause and prevent such deaths. In the USA in the year 2020, 3,400 babies below I year of age, died suddenly. Of these about 40 % were SIDS, 30 % were accidental suffocation and 25% were unknown causes. The present incidence of SIDS is about 96 deaths per 100,000 live births.
Various theories were put forward to explain the cause but most of them were not substantiated by scientific studies. Placing babies on their stomachs in the crib was the main common factor. Since this practice was abandoned, the incidence fell and held steady.
Cardiac Arrest:
'The heart stops pumping blood' is the simplest way to define the term cardiac arrest. As the heart stops so also does the circulation of blood and within a few minutes living cells begin to die. If resuscitation can be started early and properly the heart can be revived within several minutes.
Mechanism of cardiac arrest:
Lack of oxygen
Oxygen supply to the heart muscles depends on patent coronary arteries. If a coronary artery is blocked by a rupture of atheromatous plaque blood cannot go past the blocked area and lack of oxygen makes heart muscle hyperexcitable and abnormal ventricular contraction begins. If the situation does not reverse then ventricular tachycardia (VT) and ventricular fibrillation (VF) precipitate. In ventricular fibrillation, blood virtually remains in one place, and no pulse is generated. This is the usual cause of death.
Ventricular Tachycardia (VT):
In ventricular tachycardia, ventricles contact 120 to 180 times a minute. At this rate, ventricular chambers have only 0.25 seconds to 0.125 seconds to fill (normal ventricular filling time is 0.5 sec). This results in a precipitous drop in cardiac output and blood pressure, and the patient goes into shock.
In right coronary obstruction the blood supply to the Sinus Node, the normal heart pacemaker of the heart, is cut off. After the right coronary artery is blocked the heart rate slows (sinus bradycardia) and A-V(atrioventricular) nodal rhythm and various forms of heart blocks and complete heart block may develop. Complete heart block generally produces convulsions and loss of consciousness. It can also produce ventricular fibrillation, shock and death.
Uncommon but significant other causes of VF.
Hypokalemia, hypocalcemia and hypomagnesemia are known to produce VF. Special importance in clinical practice is the condition called prolongation of Q-T interval which can precipitate a fatal multifocal VT. Prolonged Q-T interval results in enhanced automaticity, which most commonly originates in the right ventricular of the conductive tissue. At the cellular level, the VT is caused by electrical re-entry. Myocardial scarring from the previous heart attack increases the likelihood of electrical reentrant circuits.
VT from a prolonged Q-T interval is called "Torsade de Pointes(meaning twisting around a point). It is an uncommon and distinctive form of polymorphic VT, characterized by a gradual change in the amplitude and twisting of QRS complexes around the isoelectric line.
[The linear regression model yielded a correction formula (for a reference RR interval of 1 second): QTLC = QT + 0.154 (1-RR) that applies to men and women. This equation corrects QT more reliably than Bazett's formula, which overcorrects the QT interval at fast heart rates and undercorrects it at low heart rates. Lower and upper limits of normal QT values in relation to RR were generated.]
The normal Q-T interval in men is 350 to 450 milliseconds and in females is 360 to 460 milliseconds.
Many medications can prolong Q-T interval. A short list of drugs are :
A cardiac drug - Quinidine.
Antihistamine – Astemizole, Diphenhydramine.
Antibiotics – Macrolide antibiotics, Quinoline group of antibiotics.
Antihypertensive – Nicardipine.
Antidepressants – Serotonin receptor blockers, Amitriptyline, Lithium
Anti-malarial – Chloroquine.
Anti-Fungal – Ranolazine
Anti-cancer – Tamoxifen
Anti-convulsant – Felbamate, Fosphenytoin.
Bronchodilators – Albuterol. Salmeterol.
CNS stimulants – Amphetamine.
Muscle relaxants – Tizanidine.
Many people die in sleep who took a cold or allergy medication before going to bed. Torsade de Pointes is likely the main reason for such deaths.
Incidence of heart attacks and fatality in the USA:
In 2018 about 30 million incidences of heart related conditions were recorded. The common heart conditions are angina, heart attacks, cardiac arrest and heart failure. And 650,000 deaths are due to heart conditions per year. The cost of treating heart related diseases, including loss of wages, totaled about $ 260 billion each year in the US.
Incidence of Out of Hospital Cardiac Arrest:
On average 360,000 incidents per year are recorded in the USA alone, which is about 1000/day. 80% of cardiac arrests happen at home, 15 % in public places and 10% in nursing homes. 2 incidences of cardiac arrest happen out of 10 million athletic events per year. The recurrent cardiac arrest rate is 20%. Males suffer much more heart attacks and the number in females increases sharply after menopause. Males in 50 -59 yr. have the highest rate - 27 % of heart attack, followed by 25 % in 60 -69 yr. age group, below 50 yr. of age is 18 %. Looking at this in another way - the incidence of first heart attack per 100, 000 population in the 40 - 49 yrs., age group is 98. After the first heart attack, life expectancy is cut short by 18 years.
Opioid Overdose:
Opium and its semisynthetic derivatives act as powerful inhibitors in the respiratory centers (located in the hindbrain). Opium causes a diminution of the respiratory drive and depth of breathing. Accumulated Carbon Dioxide (CO2) and Acid blood pH (pH less than 7.4) are powerful respiratory stimulants but fail to overcome opioids' depressive effect. The person who overdosed slips into a coma and dies. These deaths occur at night during sleep and are not noticed by family members or friends.
Strangulation, Aspiration of solids in the major airway:
Accidental swallowing of a solid object or a large piece of meat completely blocks the airway above the larynx. The person struggles when the airway is blocked but he/she is unable to clear the throat, often because of associated alcohol intoxication which is commonly seen in adults. Lack of oxygen produces ventricular arrhythmia and death due to ventricular fibrillation.
Road Accident and Gunshot Wound:
Loss of blood is the primary cause of shock and death. In some cases, direct injury to the heart results in cardiac arrest.
Pulmonary Embolism and Ruptured Arterial Aneurysm:
Massive pulmonary embolism very rarely happens in an otherwise healthy individual. Medical conditions change certain coagulation proteins favoring intravascular clotting. To name a few conditions - myeloma, polycythemia, malignancy and leg vein thrombosis. Massive pulmonary embolism prevents blood from reaching the gas exchange portion of the lung (alveoli). Lack of oxygen produces bluish discoloration of the face, lips and tongue (central cyanosis), the breathing rate increases to 30 -35/ minute, BP falls and the patient goes into shock. High flow oxygen fails to correct low oxygen in the blood. Death from massive pulmonary emboli usually happens within hours.
Aortic and abdominal aneurism, in the early stages, may remain silent. During a routine physical examination and also chest x-ray can detect silent aneurysms. When an undetected aneurysm ruptures no time should be lost in order to stop internal bleeding. Otherwise, it will be fatal.
The unexpected sudden death of a middle aged family man with young children at home brings massive grief to the family members and many problems arise from unfinished work left behind by the departed. Even with expert help no one can adequately prepare and leave things in the proper places. Humans have yet to discover what is waiting for him/her tomorrow.
Written in Memoriam of Shomik Roy, my nephew. 1971 - 2022.
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