Cardiogenic Shock: Causes, Signs and Treatment

In the realm of medical emergencies, there are situations as urgent and potentially life-threatening as cardiogenic shock. This condition arises when the heart struggles to pump blood effectively, and its consequences can be dire. In this article, we’ll explore the essential aspects of cardiogenic shock and delve into the practical world of first aid measures that can make a crucial difference when every second counts.

What is Cardiogenic Shock?

Cardiogenic shock is a severe hemodynamic condition that occurs when the heart’s pumping ability is compromised, leading to inadequate blood flow and perfusion to vital organs. It often stems from heart diseases like:

• heart attack
• heart failure
• valvular problems
• myocarditis
• cardiomyopathy

These impair the heart’s ability to effectively pump enough blood into the vascular system. As a result, there is reduced blood flow to the pulmonary and systemic circulation, leading to hypoperfusion and decreased oxygen delivery to tissues. In an attempt to compensate for the decreased cardiac output, the body may activate the venoatrial reflex, causing an increase in preload and subsequent pulmonary congestion. To support blood pressure and systemic perfusion, vasopressors may be used to constrict blood vessels and maintain the minimum venoarterial blood pressure necessary for organ function.

Incidence of Cardiogenic Shock in Australia

In Queensland, cardiogenic shock is estimated to occur in 1-2% of all people who have a heart attack. Treatment for cardiogenic shock usually involves hospitalisation in an intensive care unit, where the patient will be monitored closely and given medications to support the heart and help it pump more effectively.

A Risk to Your Cardiovascular Health

Cardiogenic shock poses significant risks and complications within the realm of cardiology and cardiovascular health. The pathophysiology of cardiogenic shock involves the left ventricle, responsible for pumping oxygen-rich blood to the body, becoming severely affected, leading to reduced cardiac output and inadequate circulation. As a result, vital organs may suffer from insufficient oxygen and nutrients, leading to organ failure. The right ventricle, which pumps blood to the lungs for oxygenation, can also be impacted, leading to pulmonary congestion and respiratory distress. Chest pain is a common symptom associated with cardiogenic shock, indicating the severity of the underlying condition.

Causes of Cardiogenic Shock

Although heart problems and coronary artery disease are the most common causes, listed below are other etiologies:

Heart attack (Myocardial Infarction)

In many cases, cardiogenic shock is the result of acute coronary syndromes such as heart attack or an acute myocardial infarction. When the blood supply to the heart muscle is blocked, the heart can’t pump enough blood to meet the body’s needs. This can lead to organ damage and eventually, death.

Severe heart rhythm problems (Arrhythmias)

Arrhythmias can lead to cardiogenic shock in a number of ways. First, arrhythmias can cause the heart to beat too fast or too slow, which can reduce the amount of blood that is pumped through the body. This can lead to a decrease in blood pressure, which can cause shock. Second, arrhythmias can cause the heart to work less efficiently, which can also lead to a decrease in blood pressure and shock. Finally, arrhythmias can cause the heart to stop beating altogether (cardiac arrest), which can lead to death.

Cardiac Tamponade

A cardiac tamponade or fluid buildup around the heart can lead to cardiogenic shock when the pressure in the pericardial sac becomes so great that it interferes with the heart’s ability to pump blood. This can cause the heart to beat erratically and eventually stop altogether.

Severe heart valve problems

Severe heart valve problems can lead to cardiogenic shock by causing the heart to pump less efficiently and preventing enough blood from reaching the rest of the body.

Severe lung disease

Severe lung disease can lead to cardiogenic shock by impairing the heart’s ability to pump blood effectively. This can result in a drop in blood pressure and decreased blood flow to the organs.

Sepsis and Septic shock

Sepsis can lead to cardiogenic shock in several ways. First, sepsis can cause low blood pressure (hypotension), which reduces the amount of blood that reaches the heart. Second, sepsis can cause the heart to become less efficient in pumping blood (myocardial dysfunction). Third, sepsis can damage the heart muscle (myocardial injury), making it less able to pump blood. Finally, sepsis can cause fluid to build up around the heart (pericardial effusion), which can further reduce its ability to pump blood.

But What is Sepsis?

Sepsis is a potentially life-threatening condition caused by the body’s response to an infection. The body’s immune system normally fights infections, but when the body’s defence against an infection damages its own tissues and organs, it develops sepsis.

Chronic Heart Failure as a Risk Factor in Australia

Cardiogenic shock in Australia is a critical concern, as it is associated with high mortality rates, underscoring the importance of effective prevention and management strategies for the identified risk factors. Chronic heart failure is one of the leading risk factors for cardiogenic shock in the country. When it is not effectively managed, it can progress to a severe state where the heart’s pumping capacity is compromised, increasing the risk of cardiogenic shock.

Signs and Symptoms of Cardiogenic Shock

The signs and symptoms of cardiogenic shock include:

• Shortness of breath
• Chest pain
• Rapid heartbeat (tachycardia)
• Nausea and vomiting
• Lightheadedness or fainting
• Cold, clammy skin
• Low blood pressure

If you or someone you know experience any of these symptoms seek medical help immediately.

Diagnosis of Cardiogenic Shock

Cardiac index, systolic blood pressure, and acidosis are important indicators that healthcare professionals monitor to assess the severity of cardiogenic shock. This often involves utilising various medical tools, such as:

• Electrocardiograms (ECGs) to assess the heart’s electrical activity and identify potential abnormalities.
• Echocardiography, a non-invasive imaging technique, provides valuable insights into the heart’s structure and function, helping to determine the underlying cause of the shock.

How Do We Treat Cardiogenic Shock?

The treatment of cardiogenic shock in Australia, as in many parts of the world, depends on the underlying cause, the patient’s clinical condition, and the availability of resources. There is no one-size-fits-all approach, and treatment may vary from case to case. However, some common strategies that healthcare providers may consider include:

1. Revascularisation: If cardiogenic shock is caused by a heart attack due to blocked coronary arteries, rapid revascularisation through procedures like angioplasty and stent placement or coronary artery bypass grafting (CABG) is often a crucial step to restore blood flow to the heart muscle.
2. Medical Therapies: Medications such as vasopressors, inotropes, and diuretics may be used to support blood pressure, improve heart function, and reduce fluid overload.
3. Mechanical circulatory support devices like intra-aortic balloon pumps (IABP) or left ventricular assist devices (LVADs) may be considered to temporarily assist the heart in pumping blood.
4. In extreme cases where conventional treatments prove insufficient, extracorporeal membrane oxygenation (ECMO) may be employed as a life-saving measure. ECMO is an advanced technology that involves routing a patient’s blood through an external device to provide oxygenation and support cardiac function, essentially taking over the role of the heart and lungs.
5. Heart Transplant: In cases where the heart is severely damaged and irreversible, heart transplantation may be the treatment of choice for long-term survival.

The type of treatment is done on a case-by-case basis, with a focus on rapidly stabilising the patient’s condition and addressing the underlying cause.

Treatment in Southport

The most common form of treatment in Australia for cardiogenic shock is percutaneous coronary intervention (PCI). This is a procedure where a small tube (catheter) is inserted into the blocked artery and a stent is placed to open up the artery. This procedure is usually done in the hospital by a cardiologist.

Inotropic Medications and Supportive Measures

To address the short-term situation and as part of critical care, inotropic agents are commonly administered to enhance the heart’s contractility and increase cardiac output such as:

• dopamine
• norepinephrine
• dobutamine

These medications work by stimulating the heart muscle, leading to improved pumping efficiency and better blood flow to vital organs. Additionally, milrinone, another potent inotropic agent, can be used to relax blood vessels and further enhance cardiac performance.

Management of Cardiogenic Shock

The first step in monitoring cardiogenic shock is to ensure that the patient’s blood pressure and heart rate are stable. If the patient’s blood pressure drops or their heart rate increases, it may be necessary to increase the number of fluids they are receiving or to start them on medication to help stabilise their condition. It is also important to closely monitor the following:

• oxygen levels and to keep an eye out for any signs of organ failure
• vital signs
• urine output – This can give clues as to how well the patient’s kidneys are functioning and whether or not they are retaining fluid.
• patient’s mental state and level of consciousness
• Cardiac output – Can give clues as to how well the heart is functioning and whether or not it is getting enough oxygen

Can Covid-19 Cause Cardiogenic Shock?

Covid-19 has been linked to cardiogenic shock in some cases. The exact cause is not yet known, but it is thought that the virus may damage the heart muscle or trigger an inflammatory response that leads to cardiac dysfunction. Clinical trials are currently underway to better understand the mechanisms behind this association and to develop targeted treatments.

First Aid for Cardiogenic Shock

Understanding cardiogenic shock and knowing how to administer essential first aid can be the difference between life and death in a critical situation. While this medical emergency is undoubtedly serious, it’s comforting to know that with the right knowledge and quick action, ordinary individuals can become heroes in a crisis. Cardiogenic shock first aid at Cnr Ferry Rd and, Cotlew St E, Southport 4215 focuses on supporting the heart and circulation while emergency medical care is sought. This may involve cardiopulmonary resuscitation (CPR), automated external defibrillation (AED), and administering medications.