By- Dr. Rachit Saxena, Senior Consultant, Cardiac Surgery, Narayana Hospital, Gurugram

Chest pain is probably one of the most dreaded symptoms in the current era surrounded by news of sudden death following brief episodes of chest pain of varying severity. This chest pain is most of the time attributed to the diagnosis of a heart attack. However, there is another entity termed as aortic dissection which commonly presents as an episode of severe chest pain but is much more sinister and fatal than the commonly encountered heart attack. This disease involves a tear in the main blood vessel arising from the heart. This can rapidly progress to a complete tear and instantaneous death. This disease is completely treatable only if identified at an early stage.

What is Aorta

The human heart is a pumping chamber meant to pump blood to the entire body including the most vital organ of the body – the brain. When the heart contacts it rejects the blood with great force into a blood vessel (a tube) called “the aorta”. This aorta in turn provides blood to all the organs through its various branches. The Aorta is a tube that has a very elastic but tough wall that helps it sustain the huge pressure of blood flow with each heartbeat throughout life. The integrity of this wall of the aorta is extremely essential for life.

What is aortic dissection

A tear in the integrity of this wall of the aorta is termed as “Aortic Dissection”. This usually begins as a small localized partial crack in one of the constituent layers of the aortic wall. However, this localized crack can rapidly progress to involve a larger length of the aorta and as it progresses it can involve the aortic branches supplying blood to the heart muscles, the brain, the kidneys, the intestine, the legs, etc. involvement of a particular branch artery signifies a significant reduction in the amount of blood the concerned organ would eventually receive. Sometimes this initial partial crack can rapidly progress to a complete breach of the aortic wall which would lead to massive internal bleeding (exsanguination) and instantaneous death.

Why Poisonous

We termed this disease as poisonous because this is the deadliest disease an individual can ever encounter. The chances of death (if untreated) are the highest for any known disease affecting human beings. Statistically speaking, around 50% of the individuals affected by the disease would die within the first 48 hours       (mortality rate of around 1% per hour for the first 48 hours). This is an exceptionally high mortality rate. Even the most dreadful advanced cancers have a much lower risk of mortality. A heart attack which in the community is considered deadly has a much lower mortality. Therefore, this disease is far more deadly than the most feared diseases ever encountered.

Death is only one aspect of the outcome. Untreated, those who are lucky to survive this disease can have permanent damage to the brain, spinal cord, kidneys, intestines, and limbs. The devastating consequences of this disease if untreated justify labeling it as poisonous.

Why Chameleon

Aortic dissection, akin to chameleons, adeptly conceals its true nature, confounding identification. Manifesting symptoms akin to various common ailments, from heart attacks to cerebral strokes, renal pain to embolic occlusions, it eludes even astute clinicians. This deceptive nature, coupled with its grave consequences, warrants labeling it as the “Poisonous Chameleon,” emphasizing its perilous and elusive character, necessitating heightened vigilance in diagnosis and management.

Who is at risk?

This deadly disease mostly affects specific ‘at-risk’ individuals. For easy understanding, we can divide them under the following heads:

Connective tissue disorders: this is a group of disorders wherein there is an inherent weakness in the tissues of an individual eg Marfan’s Syndrome. The wall of the aorta in these individuals is inherently weak and therefore it is not able to sustain the high pressure of blood flow. This weak aortic wall is highly predisposed to sudden tears in early adulthood and most of these individuals would present around the age of 25- 35 years.

Untreated hypertension: Hypertension is the term used for patients suffering from high blood pressure. Individuals with untreated hypertension will have very high pressure inside the aorta and these aortic walls are continuously exposed to exceptionally high pressure and are therefore predisposed to tear in the aorta.

Pre-existing aortic valve disease: Aortic valve is a structure that guards the blood flow from the heart into the aorta. This valve itself can malfunction due to varying disease processes both acquired or inherited. Individuals in whom this aortic valve is either leaking or has narrowed down, are predisposed to

developing weakness in the aortic wall and sustaining a subsequent aortic dissection.

Atherosclerosis: It is the process of accumulation of lipid and cholesterol plaques in the inner lining of blood vessels. This disease affects the aortic wall also and is commonly related to aging and hypercholesterolemia. The presence of these plaques produces localized weakness in the aortic wall thereby creating the possibility of initiation of a tear.

Symptoms

Chest Pain is the most common symptom present in more than 96% of patients. This pain is sharp, excruciating, localized, and most often experienced in the middle of the chest and radiating to either the neck or the back. This chest pain is often associated with dizziness, unconsciousness, limb weakness (hemiparesis), abdominal pain, or pain in the legs. Sudden death is also the presenting symptom in some cases.

Early Diagnosis

Though relatively rare, timely diagnosis of this sinister disease relies heavily on the discernment of a vigilant clinician. Frequently mistaken for a heart attack due to shared symptoms of severe chest pain, suspicion of aortic dissection should arise in several scenarios: notably in younger patients, particularly those exhibiting prominent features of Marfan’s Syndrome; when chest pain is sharp and localized; when accompanied by unconsciousness or weakness on one side of the body; or if clinical examination reveals absence of pulse in one limb. Recognition of these clues is paramount for accurate diagnosis and swift intervention. Once suspected the diagnosis is extremely easy. The quickest way to identify the disease in most cases is by doing a regular Echocardiography which can easily identify/strongly suspect the presence of a tear in the aorta. The confirmation is done by a regular CT angiography test which is easily available and takes only a few minutes to not only confirm the diagnosis but also provide all the details necessary for the treatment of the disease

Treatment

The treatment of Acute Aortic Dissection (type A) is urgent surgery. The surgery needs to be performed immediately after the diagnosis is confirmed through CT Angiography. The surgery involves replacing the diseased part of the aorta, the aortic valve, and reimplanting the coronary arteries and also the arteries carrying blood to the brain. If performed in experienced cardiac centers the mortality associated with the surgical procedure is minimal as compared to the almost certain death in unoperated.

Life after surgery

In striking contrast to the aggressive nature of the disease, the quality of life after surgical treatment is normal. Patients can perform all physical activities like any other normal individual does.