Cardiac Cycle and Left Ventricle Failure Presentation

This presentation delves into the intricacies of the human cardiac cycle, a fundamental process involving the relaxation and contraction of the heart's chambers. It details the four key phases: Isovolumic Relaxation, Ventricular Filling, Isovolumic Contraction, and Ventricular Ejection, highlighting the roles of the atria and ventricles. The presentation emphasizes the importance of valve function and the coordination necessary for efficient blood flow. A case study examines the consequences of left heart failure, specifically focusing on how damage to the left ventricle impacts cardiac output (CO) and blood pressure (BP). The analysis covers the effects of systolic and diastolic failure, the buildup of blood in the pulmonary veins, and the resulting pressure changes in the systemic circulation. The presentation also includes relevant equations for CO and BP, and references to academic sources are provided.

Human Physiology Poster Presentation
The cardiac cycle basically include overall relaxation and contraction of
ventricles as well as atria. This mainly last for approximate 0.8 second. There
are mainly four important stages of cardiac cycle that manly include
"Isovolumic relaxation, Inflow"Isovolumic contraction and Ejection. This
cycle is playing most important role in maintaining coordination to fill and
empty heart of blood. Present study mainly focus upon the manner in which
damage to the left ventricle would impact both CO and BP.
Ventricular Ejection: During this stage, contraction as well as emptying of ventricles
undertake place. While at this stage, aortic and Pulmonary artery valve closes.
Isovolumic Relaxation: At this stage, relaxation of ventricles occurs, within this pressure
get decreased and ventricles get stop to contract as well as relax. Further this has been
evaluated that by this, pulmonary artery and aortic valve close because of no pressure.
There is formative closure of valves.
Ventricular Filling Stage: During this stage blood flows through atria into the ventricles.
Along with this, it has been evaluated that in this ventricles started to get into the
relaxation phase and further lead towards significant drops in ventricles pressure.
The Cardiac Cycle Phases
The above analysis of Cardiac cycle illustrates that, human heart is basically
understood as a muscular organ. This is mainly of a fist size which effectively
pumps blood via set of connections among veins as well as arteries. It is further
define as cardiovascular system in addition to this, it has been evaluated that it
mainly include pulmonary as well as systematic circulation. Further it has been
determined that the cardiac cycle basically involves a combination of
contraction as well as relaxation of ventricles and atria. However, this has been
determined that valves failure to operate properly can lead towards generation
of disruptive blood flow in heart. This further lead towards heart sound. This
sound can be duly heard with the help of stethoscope.
The cardiac cycle mainly include different types of phases. These phases
are being effectively defined below:
Atrial Diastole: It is the stage in which heart chambers are calmed. Within
this it has been evaluated that, aortic valve as well as pulmonary artery
closes and atrioventricular valves are open. It significantly lead towards
making heart chambers to relax in effective manner. Further this has been
determined that it mainly last for 0.1 seconds.
Atrial Systole: This stage basically lasts longer for approximate 0.3
seconds. At this stage both of the ventricles get contract and blood is
forced through pulmonary truck to lungs and aorta to rest of the body.
Further it has been underlined that atrium get contracts in this stage.
Isovolumic Contraction: By this stage contraction of ventricles begin. In
addition to this, it has been understood that valve, pulmonary artery valves
and atrioventricular valves closes. However this not lead towards any form
of transformation in volume. Along with this, it has been underlined that
during this stage there is significant increase in the pressure that duly
generates in ventricles.
The cardiac cycle structure
In order to have proper understanding of the role being played by the cardiac
cycle in the blood flow movement of heart, it is firstly essential to have proper
knowledge of the cardiac structure. According to the figure 1, it has been
evaluated that human heart mainly include four chambers that further include
left as well as right halves. In this, left and right atria is being duly included in
two upper chamber. While on the other hand, left as well as right ventricles is
being posses by lower two chambers.
The above mentioned table depicts that range of pressure that was duly
observed within cardiac chambers during diastole and systole. With having
proper understanding of this lead towards having significant knowledge related
to progression among various stages of cardiac cycle.
Further according to the evaluation it has been determined that main
purpose holding by right ventricle is related to pump de oxygenated blood
via passing through pulmonary arteries as well as pulmonary truck to the
lungs. While on the other hand if it is talked about left ventricles they are
mainly having responsibility which is basically related to pumping of
newly oxygenated blood in the body via aorta.

Human Physiology Poster Presentation
CASE STUDY
The present case study underline that consequences of left heart failure to
blood pressure and cardiac output.
Cardiovascular Physiology:
Left-sided heart failure taken place as a result of the left ventricle being
bigger and pumping more blood of the human heart. In this regard, it is
identified that this kind of heart failure is segmented into two main types
named as systolic failure and diastolic failure. Now, the analysis reveals that
the former happens in a case whereby the left ventricle becomes weak
enough push enough blood. On the contrary, the latter takes place in an
instance whereby the left ventricle becomes very stiff and thus is not able to
relax, as a result of which it cannot be filled with the blood in a normal way.
Now, it is recognised that there are certain main equations within the domain
of cardiovascular physiology, as given beneath:
CO = HR x SV
BP = CO x PR
BP = (HR x SV) x PR
Where,
CO = cardiac output, HR = heart rate, SV = stroke volume and PR =
peripheral resistance.
Another important factor that needs to be taken into account for cardiac
functioning is the volume of blood that gets impacted upon by the renal
output.
In the whole functioning of the heart and the pumping of the blood, both sides
of the heart have a significant role to play as has already been outlined before.
However, the role played by the left heart is more severe which implies that its
failure will have negative consequences. The probable impacts are outlined
beneath:
• More gas exchange into the entire body as well as organs consequently
accounting to a congestive heart failure
• Backing up of blood within the human body
• Failure of the left heart will also imply failure of the left ventricle to
effectively pump blood into the systemic circulation and if this happens, then
the blood flowing within the left side of heart gets slowed or decreased.
• The build-up of blood within the pulmonary vein that awaits pumping of
blood into the left ventricle to go to the aorta along with the remaining body
• Pressure will get built up within the pulmonary vein leading to a build-up of
pressure within the pulmonary capillaries. This will lead to fluid coming out
of capillaries and entering in to the lung accounting to edema.
• This will ultimately result into the decline of pressure within the systemic
circulation resulting into reduction of BP
REFERENCES
Books and Journals
• Rennhack, J.P., and et. al., 2020. From proposal to poster: course-based
undergraduate research experience in a physiology laboratory
course. Advances in Physiology Education. 44(3). pp.459-463.
• YE, R.Z., and et. al., 2020. 1866-P: Adipocyte Hypertrophy Is Associated
with Increased Dietary Fatty Acid Storage in Adipose Tissue and Reduced
Postprandial Hepatic Fatty Acid Uptake and Esterification in Humans.
• Reynolds, A., O'Loughlin, V. and Goodwin, M., 2020. Comparing
Muscular System Coverage in Undergraduate Human Anatomy and A&P
Courses at Community Colleges and Four‐year Universities. The FASEB
Journal.34(S1). pp.1-1.
• CERO, C., and et. al., 2020. 2020-P: ß3-Adrenergic Receptors Regulate
Lipolysis and Thermogenesis in Human Brown/Beige Adipocytes.
• Jordheim, L.P. and Peters, G.J., 2020. Recent updates on purine and
pyrimidine metabolism in physiological and pathological
settings. Nucleosides, Nucleotides & Nucleic Acids. pp.1-8.
Now, human heart is segmented into left side and the right side. In this
relation, it is identified that the left side of the human heart pumps blood to
the systemic (body) whereas on the contrary, the right side of the heart
pumps blood into the pulmonary section of the body referred to as the
lungs mainly. There are 2 ventricles and 2 atria, with left and right in both.
Further there are 2 vena cava, the superior vena cava (from above the
heart) and the inferior vena cava (from below the heart). It is
acknowledged that the blood enters into the renal artery from the vena
cava and then moves into the right ventricle. The left artery is then said to
receive the oxygenated blood from the lungs and then pumps into the left
ventricle. The right ventricle pumps through the pulmonary artery into the
lungs. It is then the left ventricle pumps oxygen rich blood via the aorta to
the human body. In relation to the left side of the heart, it has been
identified that the muscle is stronger and thicker owing to the left ventricle
pumping blood within the body that is a higher pressure area
approximating around 90mmHg. Further, the right pumps in to the
pulmonary circuit that is a lower pressure area approximating around
15mmHg.