The influence of high systemic blood pressures on the right ventricle and pulmonary circuit

1927 ◽  
Vol 3 (1) ◽  
pp. 117
Keyword(s):  
Right Ventricle ◽  
Systemic Blood ◽  
Blood Pressures ◽  
The Right

scholarly journals The Physiology of the Alligator Heart: the Cardiac Cycle

1991 ◽  
Vol 158 (1) ◽  
pp. 539-564 ◽  
Author(s):  
G. SHELTON ◽  
D. R. JONES
Keyword(s):  
Right Ventricle ◽  
Cardiac Cycle ◽  
Pulmonary Arteries ◽  
Outflow Tract ◽  
Pressure Gradients ◽  
Aortic Valves ◽  
Systemic Blood ◽  
Second Stage ◽  
Blood Pressures ◽  
The Right

Pressure recordings from the heart and major arteries of the alligator show that a conventional relationship exists between the left ventricle and the right aorta. Pressure gradients from ventricle to aorta during systole are very small. Right aortic blood flow rises rapidly to a single peak and then falls more gradually until aortic valve closure. The right ventricle is connected both to the pulmonary arteries and to the left aorta. Right ventricular pressures show that systole is a two-stage process. Initially, blood leaves to the low-resistance lung circuit, though appreciable pressure gradients exist across the pulmonary outflow tract. Active contraction of the pulmonary outflow tract stops pulmonary ejection and a second-stage pressure rise is seen in the right ventricle. When systemic blood pressures are high, this second-stage pressure does not reach the levels recorded in the left aorta, and the left aortic valves remain closed so that lung and body circuits are functionally separate. An alternation of flow is found in the left aorta under these conditions, with reversed flow during systole and forward flow during diastole. Flow rates are extremely low, compared with those in the right aorta or pulmonary arteries, and the foramen of Panizza has very little significance in the cardiac cycle. If the systemic blood pressures are low, the second stage of systole in the right ventricle gives rise to pressures that are higher than those in the left aorta, the left aortic valves open and blood is ejected to the systemic circulation, giving a right-to-left shunt. This can occur with no changes in pulmonary pressures or flows. Left aortic flow is not dependent on increased constriction of the pulmonary outflow tract, which continues to function as an on-off active valve. Constriction within the lung vasculature may, on some occasions, be significant in establishing left aortic flow, but it is clear from the present work that low systemic blood pressure is a factor of crucial importance.

scholarly journals THE PHYSIOLOGY OF THE ALLIGATOR HEART: LEFT AORTIC FLOW PATTERNS AND RIGHT-TO-LEFT SHUNTS

1993 ◽  
Vol 176 (1) ◽  
pp. 247-270 ◽  
Author(s):  
D. R. Jones ◽  
G. Shelton
Keyword(s):  
Cardiac Output ◽  
Flow Pattern ◽  
Pulmonary Arteries ◽  
Systemic Blood Pressure ◽  
Aortic Flow ◽  
Pharmacological Intervention ◽  
Systemic Blood ◽  
Blood Pressures ◽  
Alkaline Tide ◽  
The Right

Blood pressures have been recorded in the heart along with pressures and flow in the aortic arches of anaesthetized and awake alligators. Systemic blood pressures were significantly lower [5.22+/−0.57 kPa (N=3) versus 9.85+/−0.46 kPa (N=5)] and cardiac outputs higher [51.6+/−3.5 ml min-1 kg-1 (N=3) versus 25.5+/−8.2 ml min-1 kg-1 (N=5)] in awake compared with anaesthetized animals. Using pharmacological interventions, two types of right-to-left shunt could be induced in all alligators. In one, established after acetylcholine (ACh) injection into the right side of the circulation, left aortic flow was an anterograde monophasic pulse which occurred when pulmonary pressure exceeded systemic blood pressure. Hence, this left aortic flow pattern could also be induced by mechanical occlusion of both pulmonary arteries. About one-quarter of cardiac output could bypass the lungs during this shunt. However, this left aortic flow pattern was never seen under any conditions other than pharmacological intervention. In the other type of shunt, induced pharmacologically by ACh injection into the left side of the circulation, left aortic flow was biphasic with a period of backflow, initiated during systole, being progressively shortened by the onset of forward flow from the right ventricle. Establishment of this type of shunt depended on the magnitude of both the systemic pressure and the pressure generated by right ventricular contraction after closure of the pulmonary outflow tract. The amount of blood bypassing the lungs during this shunt was small (13.7+/−5 % of cardiac output) but, at maximum, could be almost 25 % of cardiac output. This shunt occurred naturally in resting animals and could be maintained for substantial periods (13.2 min). The present observations confirm those made previously on anaesthetized alligators and extend previous work by showing two potential types of shunt. Finally, we suggest that right-to-left blood shunting in crocodilians may be related to the ‘alkaline tide’ that occurs after feeding, so the unique design of the central cardiovascular system in crocodilians could relate to both gastrointestinal and cardiorespiratory physiology.

scholarly journals Heart development in the lizards (Varanidae) with the greatest extent of ventricular septation

2019 ◽  
Author(s):  
Jermo Hanemaaijer ◽  
Martina Gregorovicova ◽  
Jan M. Nielsen ◽  
Antoon FM Moorman ◽  
Tobias Wang ◽  
...  
Keyword(s):  
Heart Development ◽  
Ventricular Septum ◽  
Systemic Blood ◽  
Septum Formation ◽  
Cardiac Ventricle ◽  
Vertical Septum ◽  
Blood Pressures ◽  
Left And Right ◽  
Monitor Lizards ◽  
The Right

AbstractAmong lizards, only monitor lizards (Varanidae) have a functionally divided cardiac ventricle. This enables them to sustain higher systemic blood pressures and higher metabolic rates than other reptiles of similar size. The division results from the concerted action of three partial septa, which may have homology to the full ventricular septum of mammals and archosaurs. Homology, however has only been inferred from anatomical comparisons of hearts of adult monitors whereas gene expression during heart development has not been studied. We show in developing monitors that the partial septa that separate the left and right ventricle, the ‘muscular ridge’ and ‘bulbuslamelle’, express the evolutionary conserved transcription factors Tbx5, Irx1 and Irx2, orthologues of which mark the full ventricular septum. Compaction of embryonic trabeculae contributes to the formation of these septa. The septa are positioned, however, to the right of the atrioventricular junction and they do not partake in the separation of incoming atrial blood streams. Instead, the ‘vertical septum’ within the left ventricle separates the atrial blood streams. It expresses Tbx3 and Tbx5, which orchestrate the formation of the electrical conduction axis of the full ventricular septum. These patterns of expression are more pronounced in monitors than in other lizards, and are associated with a deep electrical activation near the vertical septum, contrasting the primitive base-to-apex activation of other lizards. We conclude that current concepts of ventricular septum formation apply well to the monitor septa and that there is evolutionary conservation of ventricular septum formation among amniote vertebrates.

Comprehensive Quantification of the Right Ventricle: Pediatric Reference Values from 0 to 18 Years

2016 ◽  
Vol 64 (S 02) ◽  
Author(s):  
J. Horst ◽  
A. Karabiyik ◽  
H. Körperich ◽  
M. Fischer ◽  
E. Klusmeier ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Reference Values ◽  
The Right

Right Ventricle Mass Removal from Tricuspid Valve Apparatus: An Unusual Thromboembolic Complication of Severe Ketoacidosis

2016 ◽  
Vol 19 (2) ◽  
pp. 077
Author(s):  
Ireneusz Haponiuk ◽  
Maciej Chojnicki ◽  
Konrad Paczkowski ◽  
Wojciech Kosiak ◽  
Radosław Jaworski ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Tricuspid Valve ◽  
Mild Hypothermia ◽  
Heart Function ◽  
Thromboembolic Complication ◽  
Surgical Removal ◽  
Unusual Complication ◽  
Type I ◽  
Definitive Therapy ◽  
The Right

The presence of a pathologic mass in the right ventricle (RV) may lead to hemodynamic consequences and to a life-threatening incident of pulmonary embolism. The diagnosis of an unstable thrombus in the right heart chamber usually necessitates intensive treatment to dissolve or remove the pathology. We present a report of an unusual complication of severe ketoacidosis: thrombus in the right ventricle, removed from the tricuspid valve (TV) apparatus. A four-year-old boy was diagnosed with diabetes mellitus (DM) type I de novo. During hospitalization, a 13.9 × 8.4 mm tumor in the RV was found in a routine cardiac ultrasound. The patient was referred for surgical removal of the floating lesion from the RV. The procedure was performed via midline sternotomy with extracorporeal circulation (ECC) and mild hypothermia. Control echocardiography showed complete tumor excision with normal atrioventricular valves and heart function. Surgical removal of the thrombus from the tricuspid valve apparatus was effective, safe, and a definitive therapy for thromboembolic complication of pediatric severe ketoacidosis.<br /><br />

Ligation of a Fistula between the Left Main Coronary Artery and Both the Pulmonary Artery and the Right Ventricle

2012 ◽  
Vol 15 (2) ◽  
pp. 119 ◽  
Author(s):  
I. Halil Algin ◽  
Aytekin Yesilay ◽  
N. Murat Akcar
Keyword(s):  
Cardiopulmonary Bypass ◽  
Coronary Artery ◽  
Pulmonary Artery ◽  
Right Ventricle ◽  
Left Main Coronary Artery ◽  
Coronary Artery Fistula ◽  
Left Main ◽  
Symptomatic Disease ◽  
Coronary Artery Fistulas ◽  
The Right

The frequency of coronary artery fistula among all coronary angiography patients is 0.1% to 0.2%; however, involvement of both the pulmonary artery and the right ventricle is a rare clinical entity. A 53-year-old man patient was admitted to our clinic with rarely occurring chest pain, palpitations, and dyspnea. A coronary angiogram showed a fistula between the left main coronary artery and both the pulmonary artery and the right ventricle. We performed a ligation of this fistula without cardiopulmonary bypass. Aorta and right ventricle sutures were made, and the proximal and distal portions of the fistula were obliterated with 5-0 Prolene sutures and previously prepared Teflon felt. The patient recovered and was discharged without any complications. The surgical indications for coronary artery fistulas are symptomatic disease, an aneurysmic coronary artery, signs of heart failure, and ischemia. The surgical options in such cases�depending on whether the fistula is complicated or not�are simple ligation or transarterial ligation under cardiopulmonary bypass.

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