Cardiogenic shock

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Cardiogenic shock
Ultrasound image after cardiogenic shock due to myocarditis [1]
Specialty Cardiology
Symptoms Fatigue, rapid heartbeat, shortness of breath, hypotension, sweating, chest pain, dizziness or lightheadedness, nausea, decreased level of consciousness [2]
Complications Worsening of or causing heart failure and/or heart block, serious arrhythmias such as ventricular fibrillation, cor pulmonale, respiratory or kidney or liver dysfunction or failure, multiple organ dysfunction syndrome, cardiac arrest, death
Causes Heart attack, myocarditis, endocarditis, certain medications and substances [2]
Risk factors Heart failure, old age, hypertension [2]
Prognosis For patients where the cause is not due to a heart attack, the mortality rate is still relatively high, at about 60%; some progress has been made in treating cardiogenic shock when due to a heart attack, and the mortality rate is now somewhat lower for those with MI who survive and are treated rapidly with current therapies (February 2021) [3]

Cardiogenic shock is a medical emergency resulting from inadequate blood flow to the body's organs due to the dysfunction of the heart. Signs of inadequate blood flow include low urine production (<30 mL/hour), cool arms and legs, and decreased level of consciousness. People may also have a severely low blood pressure and heart rate.

Contents

Causes of cardiogenic shock include cardiomyopathic, arrhythmic, and mechanical. Cardiogenic shock is most commonly precipitated by a heart attack. [4]

Treatment of cardiogenic shock depends on the cause with the initial goals to improve blood flow to the body. If cardiogenic shock is due to a heart attack, attempts to open the heart's arteries may help. Certain medications, such as dobutamine and milrinone, improve the heart's ability to contract and can also be used. When these measures fail, more advanced options such as mechanical support devices or heart transplantation can be pursued.

Cardiogenic shock is a condition that is difficult to fully reverse even with an early diagnosis. [4] However, early initiation of treatment may improve outcomes. Care should also be directed to any other organs that are affected by this lack of blood flow (e.g., dialysis for the kidneys, mechanical ventilation for lung dysfunction).

Mortality rates for cardiogenic shock are high but have been decreasing in the United States. This is likely due to its rapid identification and treatment in recent decades. Some studies have suggested that this is possibly related to new treatment advances. Nonetheless, the mortality rates remain high and multi-organ failure in addition to cardiogenic shock is associated with higher rates of mortality. [5]

Signs and symptoms

The presentation is the following:[ citation needed ]

Causes

Cardiogenic shock is caused by the failure of the heart to pump effectively. It is due to damage to the heart muscle, most often from a heart attack or myocardial contusion. [6] Other causes include abnormal heart rhythms, cardiomyopathy, heart valve problems, ventricular outflow obstruction (i.e. systolic anterior motion in hypertrophic cardiomyopathy), or ventriculoseptal defects. It can also be caused by a sudden decompressurization (e.g. in an aircraft), where air bubbles are released into the bloodstream (Henry's law), causing heart failure. [7] [8] [9] [10] [11] [12] [13] [14] [15]

Diagnosis

Electrocardiogram

An electrocardiogram helps to establish the exact diagnosis and guides treatment, it may reveal:

Echocardiography

Echocardiography may show poor ventricular function, signs of PED,[ clarification needed ] rupture of the interventricular septum, an obstructed outflow tract or cardiomyopathy.[ citation needed ]

Swan-Ganz catheter

The Swan–Ganz catheter or pulmonary artery catheter may assist in the diagnosis by providing information on the hemodynamics.[ citation needed ]

Biopsy

When cardiomyopathy is suspected as the cause of cardiogenic shock, a biopsy of heart muscle may be needed to make a definite diagnosis.[ citation needed ]

Cardiac index

If the cardiac index falls acutely below 2.2 L/min/m2, the person may be in cardiogenic shock.[ citation needed ]

Treatment

Medication Therapy

Initial management of cardiogenic shock involves medications to augment the heart's function. Certain medications, such as dobutamine or milrinone, enhance the heart's pumping function and are often used first-line to improve the low blood pressure and delivery of blood to the rest of the body. [4]

Patients who have cardiogenic shock unresponsive to medication therapy may be candidates for more advanced options such as a mechanical circulatory support device. There are several types of mechanical circulatory support devices, the most common being intra-aortic balloon pumps, left ventricular assist devices, and venous-arterial extra-corporeal membrane oxygenation. It is important to note, however, that none of these devices are permanent solutions but rather are a bridge to a more definitive therapy such as a heart transplantion.

Intra-aortic balloon pump

An intra-aortic balloon pump is a device placed by a cardiac surgeon into the descending aorta. It consists of a small balloon filled with helium that helps the heart to pump blood by inflating during diastole (the resting phase of the cardiac cycle) and deflating during systole (the contracting phase of the cardiac cycle). [16] Intra-aortic balloon pumps do not directly increase cardiac output, but importantly, they decrease the amount of pressure that the heart has to pump against, thereby allowing for more blood flow and oxygen to be delivered to the heart muscles. [17]

Intra-aortic balloon pumps have been around for several decades and are most commonly used first-line of the mechanical circulatory support devices. [4] However, it is not without its potential complications. Potential complications include injury upon insertion of the device to arteries supplying the spinal cord as well as risks with any procedure such as bleeding and infection. [17] Contraindications to intra-aortic balloon pumps include aortic dissection, an abdominal aortic aneurysm, and irregularly fast heart beats. [16]

Left ventricular assist device

There are several types of left ventricular assist devices, with the Impella devices being some of the most common. This device is placed by a cardiac surgeon into the left ventricle of the heart and essentially acts as a pump, drawing blood from the left ventricle and pushing it out into the aorta so that it could be delivered to the rest of the body. [4] Unlike intra-aortic balloon pumps, the Impella acts independently from the cardiac cycle. [17] It can be adjusted to pump at faster rates to take blood out of the left ventricle and into the aorta more quickly, thereby decreasing the amount of work that the left ventricle has to do. [4] While the Impella is commonly used in settings of cardiogenic shock, some evidence suggests that it placing an Impella device in an acute cardiogenic shock setting, where the heart fails to pump suddenly, may not necessarily guarantee increased survival. [18]

Potential complications specific to an Impella device include hemolysis (shearing of the blood cells) as well as the formation of lesions on the heart valve, namely the mitral or aortic valves. [17] Contraindications to an Impella device insertion include aortic dissection, the presence of a mechanical aortic valve, and the presence of a blood clot in the left ventricle. [16]

Venous-arterial extra-corporeal membrane oxygenation

Venous-arterial extra-corporeal membrane oxygenation is a circuit support system that is meant to replace the function of the heart as it heals or awaits a more definitive treatment. [17] It consists of a circuit that essentially drains blood from a patient's venous system, runs that blood through a circulator which adds oxygen and removes carbon dioxide, and ultimately returns blood back into the patient's arterial system where the newly oxygenated blood can be delivered to the person's organs. Some evidence suggests that the combination of both an Impella device and Venous-arterial extra-corporeal membrane oxygenation may decrease the heart's pulmonary capillary wedge pressure, thereby decreasing the amount of stress on the cardiac muscles. [19]

Because Venous-arterial extra-corporeal membrane oxygenation is a very invasive procedure, it is not usually the first-line chosen device for patients in cardiogenic shock and is often reserved only for patients who have not only cardiogenic shock but also respiratory failure and/or concomitant cardiac arrest. [17]

Complications of venous-arterial extra-corporeal membrane oxygenation include an air embolism, pulmonary edema, and blood clotting in the circuit machine. [17]

See also

Related Research Articles

<span class="mw-page-title-main">Circulatory system</span> Organ system for circulating blood in animals

The circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels. The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms cardiovascular system and vascular system interchangeably with circulatory system.

<span class="mw-page-title-main">Shock (circulatory)</span> Medical condition of insufficient blood flow

Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thirst. This may be followed by confusion, unconsciousness, or cardiac arrest, as complications worsen.

<span class="mw-page-title-main">Cardiopulmonary bypass</span> Technique that temporarily takes over the function of the heart and lungs during surgery

Cardiopulmonary bypass (CPB) or heart-lung machine also called the pump or CPB pump is a machine that temporarily takes over the function of the heart and lungs during open-heart surgery by maintaining the circulation of blood and oxygen throughout the body. As such it is an extracorporeal device.

In cardiovascular physiology, stroke volume (SV) is the volume of blood pumped from the ventricle per beat. Stroke volume is calculated using measurements of ventricle volumes from an echocardiogram and subtracting the volume of the blood in the ventricle at the end of a beat from the volume of blood just prior to the beat. The term stroke volume can apply to each of the two ventricles of the heart, although when not explicitly stated it refers to the left ventricle and should therefore be referred to as left stroke volume (LSV). The stroke volumes for each ventricle are generally equal, both being approximately 90 mL in a healthy 70-kg man. Any persistent difference between the two stroke volumes, no matter how small, would inevitably lead to venous congestion of either the systemic or the pulmonary circulation, with a corresponding state of hypotension in the other circulatory system. A shunt between the two systems will ensue if possible to reestablish the equilibrium.

<span class="mw-page-title-main">Extracorporeal membrane oxygenation</span> Technique of providing both cardiac and respiratory support

Extracorporeal membrane oxygenation (ECMO), is a form of extracorporeal life support, providing prolonged cardiac and respiratory support to persons whose heart and lungs are unable to provide an adequate amount of oxygen, gas exchange or blood supply (perfusion) to sustain life. The technology for ECMO is largely derived from cardiopulmonary bypass, which provides shorter-term support with arrested native circulation. The device used is a membrane oxygenator, also known as an artificial lung.

<span class="mw-page-title-main">Cardiac catheterization</span> Insertion of a catheter into a chamber or vessel of the heart

Cardiac catheterization is the insertion of a catheter into a chamber or vessel of the heart. This is done both for diagnostic and interventional purposes.

<span class="mw-page-title-main">Cardiac cycle</span> Performance of the human heart

The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole. After emptying, the heart relaxes and expands to receive another influx of blood returning from the lungs and other systems of the body, before again contracting to pump blood to the lungs and those systems.

Pulsus paradoxus, also paradoxic pulse or paradoxical pulse, is an abnormally large decrease in stroke volume, systolic blood pressure and pulse wave amplitude during inspiration. Pulsus paradoxus is not related to pulse rate or heart rate, and it is not a paradoxical rise in systolic pressure. Normally, blood pressure drops less precipitously than 10 mmHg during inhalation. Pulsus paradoxus is a sign that is indicative of several conditions, most commonly pericardial effusion.

<span class="mw-page-title-main">Ventricular assist device</span> Medical device to assist or replace a heart

A ventricular assist device (VAD) is an electromechanical device that provides support for cardiac pump function, which is used either to partially or to completely replace the function of a failing heart. VADs can be used in patients with acute or chronic heart failure, which can occur due to coronary artery disease, atrial fibrillation, valvular disease, and other conditions.

The intra-aortic balloon pump (IABP) is a mechanical device that increases myocardial oxygen perfusion and indirectly increases cardiac output through afterload reduction. It consists of a cylindrical polyurethane balloon that sits in the aorta, approximately 2 centimeters (0.79 in) from the left subclavian artery. The balloon inflates and deflates via counter pulsation, meaning it actively deflates in systole and inflates in diastole. Systolic deflation decreases afterload through a vacuum effect and indirectly increases forward flow from the heart. Diastolic inflation increases blood flow to the coronary arteries via retrograde flow. These actions combine to decrease myocardial oxygen demand and increase myocardial oxygen supply.

A right-to-left shunt is a cardiac shunt which allows blood to flow from the right heart to the left heart. This terminology is used both for the abnormal state in humans and for normal physiological shunts in reptiles.

Venous return is the rate of blood flow back to the heart. It normally limits cardiac output.

The following outline is provided as an overview of and topical guide to cardiology, the branch of medicine dealing with disorders of the human heart. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in cardiology are called cardiologists.

Cardiothoracic anesthesiology is a subspeciality of the medical practice of anesthesiology, devoted to the preoperative, intraoperative, and postoperative care of adult and pediatric patients undergoing cardiothoracic surgery and related invasive procedures.

The Hemopump was designed to allow for temporary support of a failing heart. It is a continuous flow pump, and does not need to be synced to the rhythm of the heart. It assists in temporary heart stimulation with conditions such as cardiogenic shock following acute myocardial infarction, heart failure from cardiopulmonary bypass, and more. The pump can continually monitor the left ventricle, which allows for perpetual observation of the hearts condition. This allows for any necessary changes to be made when needed. The pump operates at speeds between two hundred and ninety and four hundred and seventy revolutions per minute.

A plot of a system's pressure versus volume has long been used to measure the work done by the system and its efficiency. This analysis can be applied to heat engines and pumps, including the heart. A considerable amount of information on cardiac performance can be determined from the pressure vs. volume plot. A number of methods have been determined for measuring PV-loop values experimentally.

Impella is a family of medical devices used for temporary ventricular support in patients with depressed heart function. Some versions of the device can provide left heart support during other forms of mechanical circulatory support including ECMO and Centrimag.

<span class="mw-page-title-main">Heart development</span> Prenatal development of the heart

Heart development, also known as cardiogenesis, refers to the prenatal development of the heart. This begins with the formation of two endocardial tubes which merge to form the tubular heart, also called the primitive heart tube. The heart is the first functional organ in vertebrate embryos.

<span class="mw-page-title-main">Acute cardiac unloading</span>

Acute cardiac unloading is any maneuver, therapy, or intervention that decreases the power expenditure of the ventricle and limits the hemodynamic forces that lead to ventricular remodeling after insult or injury to the heart. This technique is being investigated as a therapeutic to aid after damage has occurred to the heart, such as after a heart attack. The theory behind this approach is that by simultaneously limiting the oxygen demand and maximizing oxygen delivery to the heart after damage has occurred, the heart is more fully able to recover. This is primarily achieved by using temporary minimally invasive mechanical circulatory support to supplant the pumping of blood by the heart. Using mechanical support decreases the workload of the heart, or unloads it.

<span class="mw-page-title-main">Pathophysiology of heart failure</span>

The main pathophysiology of heart failure is a reduction in the efficiency of the heart muscle, through damage or overloading. As such, it can be caused by a wide number of conditions, including myocardial infarction, hypertension and cardiac amyloidosis. Over time these increases in workload will produce changes to the heart itself:

References

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  2. 1 2 3 "Cardiogenic shock – Symptoms and causes". Mayo Clinic. Retrieved 22 May 2020.
  3. ↑ Schrage B, Becher PM, Goßling A, Savarese G, Dabboura S, Yan I, et al. (April 2021). "Temporal trends in incidence, causes, use of mechanical circulatory support and mortality in cardiogenic shock". ESC Heart Failure. 8 (2): 1295–1303. doi:10.1002/ehf2.13202. PMC   8006704 . PMID   33605565.
  4. 1 2 3 4 5 6 Vahdatpour C, Collins D, Goldberg S (April 2019). "Cardiogenic Shock". Journal of the American Heart Association. 8 (8): e011991. doi:10.1161/JAHA.119.011991. PMC   6507212 . PMID   30947630.
  5. ↑ Thiele H, de Waha-Thiele S, Freund A, Zeymer U, Desch S, Fitzgerald S (August 2021). "Management of cardiogenic shock". EuroIntervention. 17 (6): 451–465. doi:10.4244/EIJ-D-20-01296. PMC   9724885 . PMID   34413010.
  6. ↑ International Trauma Life Support for Emergency Care Providers (8 ed.). Pearson Education Limited. 2018. pp. 172–173. ISBN   978-1292-17084-8.
  7. ↑ Rippe JM, Irwin RS (2003). Irwin and Rippe's intensive care medicine. Philadelphia: Lippincott Williams & Wilkins. ISBN   978-0-7817-3548-3. OCLC   53868338.[ page needed ]
  8. ↑ Marino PL (1998). The ICU book. Baltimore: Williams & Wilkins. ISBN   978-0-683-05565-8. OCLC   300112092.[ page needed ]
  9. ↑ Society of Critical Care Medicine. (2001). Fundamental Critical Care Support. Society of Critical Care Medicine. ISBN   978-0-936145-02-0. OCLC   48632566.[ page needed ]
  10. ↑ Harrison's Principles of Internal Medicine (16th ed.). The McGraw-Hill Companies. 2005. ISBN   0-07-140235-7. Archived from the original on 2012-08-04.
  11. ↑ Goldman L, Ausiello D, eds. (2003). Cecil Textbook of Medicine (22nd ed.). W. B. Saunders Company. ISBN   0-7216-9652-X. Archived from the original on 2010-06-16.
  12. ↑ Warrell DA, Cox TM, Firth JD, Benz EJ, eds. (2003). The Oxford Textbook of Medicine (Fourth ed.). Oxford University Press. ISBN   0-19-262922-0. Archived from the original on 2006-09-23.
  13. ↑ Cheatham ML, Block EF, Smith HG, Promes JT. Shock: An Overview (PDF). Surgical Critical Care Service, Department of Surgical Education (Report). Orlando, Florida: Orlando Regional Medical Center. Archived from the original (PDF) on 2017-06-22.
  14. ↑ "Cardiogenic shock". Department of Anaesthesia and Intensive Care of The Chinese University of Hong Kong . Archived from the original on 2017-07-23.
  15. ↑ "Introduction to management of shock for junior ICU trainees and medical students". Department of Anaesthesia and Intensive Care of The Chinese University of Hong Kong . Archived from the original on 2017-07-27.
  16. 1 2 3 Geller BJ, Sinha SS, Kapur NK, Bakitas M, Balsam LB, Chikwe J, et al. (August 2022). "Escalating and De-escalating Temporary Mechanical Circulatory Support in Cardiogenic Shock: A Scientific Statement From the American Heart Association". Circulation. 146 (6): e50–e68. doi: 10.1161/CIR.0000000000001076 . PMID   35862152.
  17. 1 2 3 4 5 6 7 Combes A, Price S, Slutsky AS, Brodie D (July 2020). "Temporary circulatory support for cardiogenic shock". Lancet. 396 (10245): 199–212. doi: 10.1016/S0140-6736(20)31047-3 . PMID   32682486.
  18. ↑ Ni Hlci, Tamara; Boardman, Henry MP; Baig, Kamran; Aifesehi, Paul E.; Stafford, Jody L.; Cernei, Cristina; Bodger, Owen; Westaby, Stephen; et al. (Cochrane Heart Group) (2018-04-12). "Mechanical assist devices for acute cardiogenic shock". Cochrane Database of Systematic Reviews. 2018 (4): CD013002. doi:10.1002/14651858.CD013002. PMC   6494568 .
  19. ↑ Russo JJ, Aleksova N, Pitcher I, Couture E, Parlow S, Faraz M, et al. (February 2019). "Left Ventricular Unloading During Extracorporeal Membrane Oxygenation in Patients With Cardiogenic Shock". Journal of the American College of Cardiology. 73 (6): 654–662. doi: 10.1016/j.jacc.2018.10.085 . PMID   30765031.
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