Left Ventricle Heart
Introduction[edit | edit source]
The left ventricle is an integral part of the cardiovascular system. Left ventricular contraction forces oxygenated blood through the aortic valve to be distributed to the entire body. With such an important role, decreased function caused by injury or maladaptive change can induce symptoms of the disease
The left ventricle pumps blood at higher pressures compared to the rest of the other heart chambers, as it faces a much higher workload and mechanical afterload. In comparison to that of the right ventricle, the free wall of the left ventricle is much thicker.
Anatomy[edit | edit source]
The left ventricle is conical in shape with an anteroinferiorly projecting apex and is longer with thicker walls than the right ventricle. It is separated from the right ventricle by the interventricular septum, which is concave in shape (i.e. bulges into the right ventricle). The ventricular wall is thickest at the base and thins to only 1-2 mm at the apex.
There are two papillary muscles that attach to the mitral valve via chordae tendineae:
- anterior lateral (anterolateral)
- posterior medial (posteromedial)
Blood supply[edit | edit source]
Venous drainage: great cardiac vein, middle cardiac vein, and posterior vein of the left ventricle: drain into the coronary sinus; tiny myocardial thebesian veins drain directly into the left ventricle
Function[edit | edit source]
Providing sufficient cardiac output to maintain blood flow to other organ systems is the primary function of the left ventricle. Cardiac output is the result of systolic contraction of the left ventricle, which can be influenced by preload, afterload, and contractility.
Cardiac output (CO) is defined as the amount of blood that is pumped out of the heart in a given time. Heart rate (HR) is the number of heartbeats in a given time, often recorded as beats per minute (bpm). Stroke volume (SV) is the volume of blood ejected in a single ventricular contraction. Cardiac output can be calculated using the following equations:
- CO = HR * SV
- SV = end-diastolic volume (EDV) – end-systolic volume (ESV)
Cardiac output cannot be measured clinically, so ejection fraction is a commonly used index to estimate heart contractility. Left ventricular ejection fraction (LVEF) is the volume of blood pumped out of the heart during systole relative to the volume in the left ventricle at the end of diastole. LVEF is calculated using the following equation:
- LVEF = SV / EDV
Organ Connection[edit | edit source]
The left ventricle connects nearly all organ systems through its function to pump oxygenated blood to the body. Left ventricular failure would likely result in impairment to all other organ systems.
- Organs may react to low ventricular function by initiating mechanisms to increase blood delivery eg person might experience syncopal episodes due to a lack of blood flow to the brain, or their kidneys might start to release renin to elevate blood pressure.
- Decreased cardiac output can also lead to adrenal release of epinephrine to increase heart rate, and subsequently blood pressure, thus increasing blood supply to vital organs such as the brain.
- Left ventricular failure may cause blood to back up into the lungs and cause pulmonary edema. This edema can lead to pulmonary hypertension and excessive strain to the right atrium and ventricle. The fluid will again back up, this time into the vena cava, and can cause liver pathologies and cause portal hypertension
Related pathology[edit | edit source]
- Left ventricular (LV) dilatation and LV hypertrophy (acknowledged precursors of myocardial dysfunction and ultimately of heart failure).
- Left ventricular heart failure
- Coronary Artery Disease
- Left ventricular assist device
- Cardiac neoplasms
Physiotherapy[edit | edit source]
Cardiac rehabilitation is a complex, interprofessional intervention customized to individual patients with various cardiovascular diseases such as:
- Coronary artery disease (CAD),
- Heart failure
- Myocardial infarctions
- Patients who have undergone cardiovascular interventions such as coronary angioplasty or coronary artery bypass grafting.
References[edit | edit source]
- Berman MN, Tupper C, Bhardwaj A. Physiology, Left Ventricular Function. [ Updated 2020 Sep 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-.Available:https://www.ncbi.nlm.nih.gov/books/NBK541098/ (accessed 18.7.2021)
- Radiopedia LV Available:https://radiopaedia.org/articles/left-ventricle (accessed 18.7.2021)
- AUTHOR=Sahiti Floran, Morbach Caroline, Cejka Vladimir, Albert Judith, Eichner Felizitas A., Gelbrich GÃ¶tz, Heuschmann Peter U., StÃ¶rk Stefan TITLE=Left Ventricular Remodeling and Myocardial Work: Results From the Population-Based STAAB Cohort Study JOURNAL=Frontiers in Cardiovascular Medicine VOLUME=8 YEAR=2021 PAGES=527 Available:https://www.frontiersin.org/articles/10.3389/fcvm.2021.669335/full (accessed 18.7.2021)