Abstract 5932: The Differences of Echocardiography and MRI Findings in Patients with Constrictive Pericarditis According to the History of Chest Radiation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kye Hun Kim ◽  
DaLi Feng ◽  
James Glockner ◽  
Matthew Martinez ◽  
William D Edwards ◽  
...  
Keyword(s):  
Constrictive Pericarditis ◽  
Left Ventricular ◽  
Volume Index ◽  
Significant Finding ◽  
Mri Findings ◽  
Mitral Inflow ◽  
Myocardial Disease ◽  
Group I ◽  
History Of ◽  
Group Ii

Background: Radiation therapy (RT) to the chest may induce various combined cardiac problems such as constrictive pericarditis (CP), restrictive myocardial disease, and coronary artery disease. Therefore, it was hypothesized that the MRI and transthoracic echocardiographic (TTE) findings in patients with CP may differ according to the history of RT. Methods: A total of 68 patients with CP who performed both TTE and MRI study at Mayo Clinic from 2002 to 2008 were reviewed and divided into two groups according to the history of RT; RT group (group I, n=13, 53.6±9.8 years, 8 males) versus no RT group (group II, n=55, 59.0±14.8, 45 males). Results: The results of TTE study were summarized in table . Early diastolic velocity of septal mitral annulus (E′) and deceleration time (DT) of mitral inflow was significantly lower, and the ratio of early diastolic mitral inflow velocity (E) to E′ is significantly higher in group I than in group II. Left atrial volume index (LAVI) was significantly lower and LA area and left ventricular end-diastolic dimension (LVEDD) was significantly smaller in group I than in group II. Delayed enhancement of pericardium was the only significant finding in MRI and significantly prevalent in group I than in group II (100.0% in group I vs 63.6% in group II, p=0.012). The other MRI findings including pericardial thickness, left ventricular and right ventricular ejection fraction, and the presence of pericardial and pleural effusion were not different between the groups. Conclusion: In CP patients with the history of RT compared to patients without history of RT, E′ and DT was significantly lower, LAVI and LVEDD were smaller, pericardial DE in MRI was invariably found. The lower E′ velocity and decreased chamber size and volumes may be explained by RT induced coexisting myocardial disease. TTE findings of the patients

Abstract 19826: Utility of Stroke Volume Index for Stratification of Patients With Low Gradient Severe Aortic Stenosis and Normal Left Ventricular Ejection Fraction

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Hong Shen ◽  
Brandon Stacey ◽  
Bob Applegate ◽  
David Zhao ◽  
Sujethra Vasu ◽  
...  
Keyword(s):  
Stroke Volume Index ◽  
Left Ventricular ◽  
Group Iv ◽  
Low Flow ◽  
Volume Index ◽  
Left Ventricular Ejection ◽  
Ventricular Ejection Fraction ◽  
Cumulative Survival ◽  
Group I ◽  
Group Ii

Background: Decision of intervention for low gradient severe aortic stenosis (AS) with normal left ventricular ejection fraction (LVEF) is clinically challenging. The study was to determine the impact of stroke volume index (SVi) on prognosis in patients (pts) with AS. Methods: We examined 410 pts with moderate or severe AS and normal EF (≥50%). Pts were divided into four groups based on aortic valve area (AVA), mean pressure gradient (MPG) and SVi: Group I: low flow low gradient severe AS (AVA≤1.0cm 2 , MPG<40mmHg and SVi<35mL/m 2 , n=75); Group II: normal flow low gradient severe AS (AVA≤1.0cm 2 , MPG<40mmHg and SVi≥35mL/m 2 , n=97); Group III: severe AS with matched gradient-AVA (AVA≤1.0cm 2 and MPG≥40mmHg, n=88); Group IV: moderate AS (AVA>1.0cm 2 and MPG>20mmHg, <40 mmHg, n=150). Aortic valve gradients, AVA and SVi were assessed by echocardiography. Clinical charts were reviewed. Mean follow-up duration was 3.2±1.6 years. Results: Group I had higher prevalence of atrial fibrillation, more pronounced LV hypertrophy, lower SVi, smaller AVA, higher valvuloarterial impedance (Zva) (Table) and lower 3-year cumulative survival compared to Group II and Group IV (61% vs. 75% and 80%, p=0.004). Group II had a 3-year cumulative survival similar to moderate AS (75% vs. 80%, p>0.05). In pts with medical management, Group I and Group III had lower 3-year cumulative survival in comparison with Group II and Group IV (48% and 56% vs. 73% and 76%, p=0.001). Multivariate analysis showed SVi was a strong predictor of mortality in low gradient severe AS (HR 0.95, CI: 0.91-0.99, P=0.02). However, in gradient-AVA matched severe AS and moderate AS, SVi was not associated with mortality (p>0.05). Conclusions: Without AS intervention, low flow low gradient severe AS with normal EF carries poor prognosis similar to high gradient AS, but normal flow low gradient AS does not, suggesting that SVi may be used to identify the pts benefiting most from AS intervention in pts with low gradient AS.

Abstract 2844: Preload Augmentation by Leg Elevation is Helpful in Triaging the Patients with Grade 1 Diastolic Dysfunction

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Eui-Young Choi ◽  
Sung-Ai Kim ◽  
Sang Jae Rhee ◽  
Ae Young Her ◽  
Chi Young Shim ◽  
...  
Keyword(s):  
Diastolic Dysfunction ◽  
Previous History ◽  
Regional Wall Motion ◽  
Left Ventricular ◽  
Mitral Inflow ◽  
Additional Information ◽  
Group I ◽  
Significant Difference ◽  
History Of ◽  
Mitral Inflow Velocity

Grade 1 diastolic dysfunction (DD) is a spectrum of a variety of conditions. Objectives: We sought to investigate whether the responses of mitral inflow and annular velocity to leg elevation can provide additional information regarding triaging patients with grade 1 DD. One hundred fifty-four consecutive patients with hypertension with abnormal left ventricular (LV) relaxation on Doppler mitral inflow (early (E)/late (A) mitral inflow velocity <0.75 or deceleration time > 240 ms) were enrolled. Patients with LV ejection fractions less than 50%, a previous history of ischemic heart disease, inducible regional wall motion abnormality, valvular or myocardial disease, or any other volume overloading diseases were excluded. After resting evaluation, echo-Doppler measurements were performed during passive leg elevation and symptom-limited graded bicycle exercise. Patients were divided into two groups according to resting E/E’: Group I (E/E’<15) and II (E/E’≥15, n=23). Group I subjects were further subdivided into IA (persistent E/E’ <15, n=112) and IB (change to E/E’≥15, n=19) according to response to leg elevation. Group II had lower systolic (S’), early (E’), and late (A’) diastolic annular velocity, and diastolic reserve index to exercise (E’xΔE’50W) and higher LV elastance index (E/E’/stroke volume) than that of group IA; there was no significant difference compared to group IB. Group IB had more female predominance, older age, lower E’, higher diastolic elastance index, and higher E/E’ at 25W and 50W exercise accompanied by lower exercise capacity compared to group IA. Preload augmentation by leg elevation might provide additional information in triaging patients with grade 1 DD.

Effects of Rest and Exercise on Cardiac Blood Volume Determinations

1997 ◽  
Vol 36 (08) ◽  
pp. 259-264
Author(s):  
N. Topuzović
Keyword(s):  
Radionuclide Ventriculography ◽  
Left Ventricular ◽  
Peak Exercise ◽  
Volume Determination ◽  
Group I ◽  
Lv Volumes ◽  
Group Ii ◽  
Lv Volume

Summary Aim: The purpose of this study was to investigate the changes in blood activity during rest, exercise and recovery, and to assess its influence on left ventricular (LV) volume determination using the count-based method requiring blood sampling. Methods: Forty-four patients underwent rest-stress radionuclide ventriculography; Tc-99m-human serum albumin was used in 13 patients (Group I), red blood cells was labeled using Tc-99m in 17 patients (Group II) in vivo, and in 14 patients (Group III) by modified in vivo/in vitro method. LV volumes were determined by a count-based method using corrected count rate in blood samples obtained during rest, peak exercise and after recovery. Results: In group I at stress, the blood activity decreased by 12.6 ± 5.4%, p <0.05, as compared to the rest level, and increased by 25.1 ± 6.4%, p <0.001, and 12.8 ± 4.5%, p <0.05, above the resting level in group II and III, respectively. This had profound effects on LV volume determinations if only one rest blood aliquot was used: during exercise, the LV volumes significantly decreased by 22.1 ± 9.6%, p <0.05, in group I, whereas in groups II and III it was significantly overestimated by 32.1 ± 10.3%, p <0.001, and 10.7 ± 6.4%, p <0.05, respectively. The changes in blood activity between stress and recovery were not significantly different for any of the groups. Conclusion: The use of only a single blood sample as volume aliquot at rest in rest-stress studies leads to erroneous estimation of cardiac volumes due to significant changes in blood radioactivity during exercise and recovery.

scholarly journals Empagliflozin does not change cardiac index nor systemic vascular resistance but rapidly improves left ventricular filling pressure in patients with type 2 diabetes: a randomized controlled study

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Matthias Rau ◽  
Kirsten Thiele ◽  
Niels-Ulrik Korbinian Hartmann ◽  
Alexander Schuh ◽  
Ertunc Altiok ◽  
...  
Keyword(s):  
Cardiac Index ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Resistance Index ◽  
Stroke Volume Index ◽  
Left Ventricular ◽  
Volume Index ◽  
Hemodynamic Parameters ◽  
Mitral Inflow ◽  
Ventricular Filling Pressure

Abstract Background In the EMPA-REG OUTCOME trial (Empagliflozin Cardiovascular Outcome Event Trial) treatment with the sodium-glucose cotransporter-2 (SGLT2) inhibitor empagliflozin significantly reduced heart failure hospitalization (HHF) in patients with type 2 diabetes mellitus (T2D) and established cardiovascular disease. The early separation of the HHF event curves within the first 3 months of the trial suggest that immediate hemodynamic effects may play a role. However, hitherto no data exist on early effects of SGLT2 inhibitors on hemodynamic parameters and cardiac function. Thus, this study examined early and delayed effects of empagliflozin treatment on hemodynamic parameters including systemic vascular resistance index, cardiac index, and stroke volume index, as well as echocardiographic measures of cardiac function. Methods In this placebo-controlled, randomized, double blind, exploratory study patients with T2D were randomized to empagliflozin 10 mg or placebo for a period of 3 months. Hemodynamic and echocardiographic parameters were assessed after 1 day, 3 days and 3 months of treatment. Results Baseline characteristics were not different in the empagliflozin (n = 22) and placebo (n = 20) group. Empagliflozin led to a significant increase in urinary glucose excretion (baseline: 7.3 ± 22.7 g/24 h; day 1: 48.4 ± 34.7 g/24 h; p < 0.001) as well as urinary volume (1740 ± 601 mL/24 h to 2112 ± 837 mL/24 h; p = 0.011) already after one day compared to placebo. Treatment with empagliflozin had no effect on the primary endpoint of systemic vascular resistance index, nor on cardiac index, stroke volume index or pulse rate at any time point. In addition, echocardiography showed no difference in left ventricular systolic function as assessed by left ventricular ejections fraction and strain analysis. However, empagliflozin significantly improved left ventricular filling pressure as assessed by a reduction of early mitral inflow velocity relative to early diastolic left ventricular relaxation (E/eʹ) which became significant at day 1 of treatment (baseline: 9.2 ± 2.6; day 1: 8.5 ± 2.2; p = 0.005) and remained apparent throughout the study. This was primarily attributable to reduced early mitral inflow velocity E (baseline: 0.8 ± 0.2 m/s; day 1: 0.73 ± 0.2 m/sec; p = 0.003). Conclusions Empagliflozin treatment of patients with T2D has no significant effect on hemodynamic parameters after 1 or 3 days, nor after 3 months, but leads to rapid and sustained significant improvement of diastolic function. Trial registration EudraCT Number: 2016-000172-19; date of registration: 2017-02-20 (clinicaltrialregister.eu)

scholarly journals TO STUDY THE ONSET AND PROGRESSION OF AIRWAY ABNORMALITY IN TERMS OF ALTERATION IN PFT IN ASYMPTOMATIC SMOKERS.

2019 ◽  
Vol 3 (11) ◽  
Author(s):  
Dr. Hitesh Kumar Solanki ◽  
Dr. Omnath P Yadav ◽  
Dr. Anita J Gojiya
Keyword(s):  
Lung Function ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Medical College ◽  
Group I ◽  
Significant Difference ◽  
History Of ◽  
Young Smokers ◽  
The Mean ◽  
Group Ii

The study was conducted in department of physiology, B J Medical College, Ahmedabad from Mar. 2012 to Feb. 2013. This was a cross-sectional study to evaluate the effect of smoking on lung   function and serum lipids in asymptomatic smokers   and comparable non   smokers. The mean of the various spirometric parameters were calculated of the subjects for both the groups. The mean FVC in group I and group II was 2.60 ± 0.62 L and 4.10 ± 0.64L respectively. The mean FEV1 in group I was 1.91 ± 0.57L and     3.19 ± 0.77L in group II Group I had mean FEF25% - 75% and PEFR of 1.98 ± 0.67L/sec and 4.50 ± 1.57L/sec respectively. Group II had mean FEF25 – 75% of 4.22 ± 1.23L/sec and a mean PEFR of 7.22 ± 1.42L/sec. In young smokers and asymptomatic, still the spirometric values were significantly deranged as compared to controls. Even smokers with history of less pack years of smoking also had significant abnormalities of lung function. All he spirometric values in the two groups had statistically highly significant difference and were higher in non-smokers as compared to smokers. The spirometric values were reduced in smokers with history of smoking for as low as two pack years. Keywords: Progression, PFT, Asymptomatic & Smokers

scholarly journals Empagliflozin does not change cardiac index nor systemic vascular resistance but rapidly improves left ventricular filling pressure in patients with type 2 diabetes: a randomized controlled study 

2020 ◽  
Author(s):  
Matthias Rau ◽  
Kirsten Thiele ◽  
Niels-Ulrik Korbinian Hartmann ◽  
Alexander Schuh ◽  
Ertunc Altiok ◽  
...  
Keyword(s):  
Cardiac Index ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Resistance Index ◽  
Stroke Volume Index ◽  
Left Ventricular ◽  
Volume Index ◽  
Hemodynamic Parameters ◽  
Mitral Inflow ◽  
Ventricular Filling Pressure

Abstract Background: In the EMPA-REG OUTCOME trial (Empagliflozin Cardiovascular Outcome Event Trial) treatment with the sodium-glucose cotransporter-2 (SGLT2) inhibitor empagliflozin significantly reduced heart failure hospitalization (HHF) in patients with type 2 diabetes mellitus (T2D) and established cardiovascular disease. The early separation of the HHF event curves within the first 3 months of the trial suggest that immediate hemodynamic effects may play a role. However, hitherto no data exist on early effects of SGLT2 inhibitors on hemodynamic parameters and cardiac function. Thus, this study examined early and delayed effects of empagliflozin treatment on hemodynamic parameters including systemic vascular resistance index, cardiac index, and stroke volume index, as well as echocardiographic measures of cardiac function.Methods: In this placebo-controlled, randomized, double blind, exploratory study patients with T2D were randomized to empagliflozin 10 mg or placebo for a period of 3 months. Hemodynamic and echocardiographic parameters were assessed after 1 day, 3 days and 3 months of treatment. Results: Baseline characteristics were not different in the empagliflozin (n=22) and placebo (n=20) group. Empagliflozin led to a significant increase in urinary glucose excretion (baseline: 7.3 ± 22.7 g/24 hrs; day 1: 48.4 ± 34.7 g/24 hrs; p<0.001) as well as urinary volume (1740 ± 601 mL/24 hrs to 2112 ± 837 mL/24 hrs; p=0.011) already after one day compared to placebo. Treatment with empagliflozin had no effect on the primary endpoint of systemic vascular resistance index, nor on cardiac index, stroke volume index or pulse rate at any time point. In addition, echocardiography showed no difference in left ventricular systolic function as assessed by left ventricular ejections fraction and strain analysis. However, empagliflozin significantly improved left ventricular filling pressure as assessed by a reduction of early mitral inflow velocity relative to early diastolic left ventricular relaxation (E/e’) which became significant at day 1 of treatment (baseline: 9.2 ± 2.6; day 1: 8.5 ± 2.2; p=0.005) and remained apparent throughout the study. This was primarily attributable to reduced early mitral inflow velocity E (baseline: 0.8 ± 0.2 m/sec; day 1: 0.73 ± 0.2 m/sec; p=0.003). Conclusions: Empagliflozin treatment of patients with T2D has no significant effect on hemodynamic parameters after 1 or 3 days, nor after 3 months, but leads to rapid and sustained significant improvement of diastolic function.

Abstract 4510: Pulmonary Hypertension before Transcatheter Aortic Valve Implantation Is Reversible and Lacks Prognostic Significance

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Abdullah M Al Ali ◽  
Brad Munt ◽  
Lukas Altwegg ◽  
Karin Humphries ◽  
Ronald Carere ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Pulmonary Artery ◽  
Prognostic Significance ◽  
Left Ventricular ◽  
Group Iii ◽  
Transcatheter Aortic Valve ◽  
Group I ◽  
Group Ii ◽  
One Year ◽  
Valve Implantation

The prognostic significance of pulmonary hypertension (PH) and the potential for reversibility in the setting of aortic stenosis (AS) have been debated. We examined the clinical correlates and prognostic significance of PH in high risk elderly patients with symptomatic severe AS undergoing transcatheter aortic valve implantation (AVI). AVI was performed in 143 patients. Adequate echocardiographic estimation of baseline pulmonary artery systolic pressure was available in 115 (80%). Patients were divided into 3 groups according to baseline pulmonary artery pressure estimated by transthoracic echocardiogram: I: <30 mmHg, II: 30 –50 mmHg and III: >50 mmHg. Clinical and echocardiographic follow-up was obtained at 1, 6 and 12 months after AVI. Group I consisted of 17 patients (15%), group II 58 patients (50%) and group III 40 patients (35%). At baseline the three groups were similar in terms of age, functional status, presence of severe pulmonary disease, aortic valve area and mean gradient. Patients with severe PH (group III) were more likely to have left ventricular dysfunction (LVEF <50%) than patients with mild to moderate PH (groups I and II) (52% vs. 21%, p=0.002) and had more severe mitral regurgitation (grade ≥ 3 in 68% vs. 41%, p =0.0002). At one month, systolic pulmonary artery pressure fell significantly in group III (11.0 ± 14.3 mmHg, p=0.0008) and this reduction was maintained at 6 months. However, the changes in group I (increase of 7.1 ± 8.7 mmHg, p=0.07) and group II (decrease of 0.9 ± 9.3 mmHg, p=0.53) were not significant. Mortality at one year following AVI was 21%, but was not related to severity of PH. Using group III as a reference, hazard ratios were 0.83 (95% CI: 0.24 –2.9) for group I and 0.88 (95% CI: 0.4 –1.9) for group II. In elderly patients with severe AS treated with transcatheter AVI, severe PH is associated with more depressed left ventricular function and more severe mitral regurgitation. Severe PH is associated with a significant and greater fall in pulmonary pressure following AVI and does not influence one year survival.

Echocardiographic assessment of LV mass in rabbits: models of pressure and volume overload hypertrophy

1993 ◽  
Vol 265 (6) ◽  
pp. H2066-H2072 ◽  
Author(s):  
J. F. Plehn ◽  
E. Foster ◽  
W. N. Grice ◽  
M. Huntington-Coats ◽  
C. S. Apstein
Keyword(s):  
Pressure Overload ◽  
Volume Overload ◽  
Accurate Method ◽  
Aortic Insufficiency ◽  
Left Ventricular ◽  
Cross Sectional ◽  
Group I ◽  
Lv Mass ◽  
Wet Weight ◽  
Group Ii

We describe a method for the noninvasive measurement of left ventricular mass in small animals using two-dimensionally guided M-mode echocardiography. We compared echocardiographic cross-sectional area (CSA) and cubed-based volumetric indexes of left ventricular (LV) mass with postmortem wet weight in renovascular hypertension-induced pressure overload (group I) and acute aortic insufficiency-induced volume overload (group II) models of ventricular hypertrophy. CSA and cubed echocardiographic indexes correlated well with wet weight from a combination of group I and II animals and their controls (r = 0.89, P < 0.001 for both groups). Separate analyses of groups I and II also demonstrated significant relationships between mass indexes and wet weight using CSA and cubed formulas, respectively, in both pressure (r = 0.57, P = 0.01 and r = 0.71, P < 0.001) and volume (r = 0.90 and r = 0.89, P < 0.001) overload models. Echocardiographically predicted LV mass derived from cubed and CSA regression formulas was 89 and 56% sensitive for pressure overload hypertrophy in group I and 100% sensitive (both cubed and CSA methods) for volume overload hypertrophy in group II. Cubed and CSA mass regression formulas were 60 and 80% specific for hypertrophy in group I and 100 and 90% specific in group II. Normalization of predicted LV mass for body weight added little to the overall technique accuracy with measured sensitivities of 83 and 75% and specificities of 92 and 77%, respectively, for cubed and CSA methods. Two-dimensionally guided M-mode echocardiography provides a reasonably accurate method of LV mass determination in rabbits with pressure- or volume-overloaded ventricles.

scholarly journals Interdialytic Weight Gain and Its Relation to Outcome among Patients on Maintenance Hemodialysis

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
M K Ibrahim ◽  
O M M Kamal ◽  
M S Hassan ◽  
M M M Khalifa
Keyword(s):  
Weight Gain ◽  
Vena Cava ◽  
Total Body Weight ◽  
Left Ventricular ◽  
Morbidity And Mortality ◽  
Maintenance Hemodialysis ◽  
Interdialytic Weight Gain ◽  
Group I ◽  
Cardiovascular Morbidity And Mortality ◽  
Group Ii

Abstract Introduction The most common cause of mortality among chronic hemodialysis (HD) patients is cardiovascular disease. Hypervolemia is an important risk factor for hypertension and cardiovascular mortality in HD patients that include chronic volume overload and interdialytic weight gain (IDWG).IDWG affects cardiovascular morbidity and mortality Daily fluctuations in extracellular fluid volume might promote cardiac remodeling resulting in left ventricular hypertrophy (LVH) and cardiac fibrosis. Aim of the study to assess interdialytic weight gain and (its relation to morbidity and mortality) among patients on maintenance hemodialysis. Patient and methods 100 ESRD patients on regular hemodialysis included in study in Ain Shams University hospitals in march 2016 and followed up after one year in march 2017. Type of study cohort study Patients were divided into two groups according to interdialytic weight gain (IDWG): Group I (high IDWG) 50 patients with Absolute weight gain 4kg or more. Or relative IDWG more than 3.5% of total body weight. Group II (low IDWG) 50 patients with absolute weight gain less than 3kg Or relative IDWG less than 3.5% of total body weight. Echocardiography (TTE) for all patients at the start of the study and followed up after one year for detecting outcomes included all-cause mortality, cardiovascular mortality, hospitalization for heart failure/volume overload, hospitalization for myocardial infarction, stroke. Results we found that patient with high (IDWG) group II has significantly higher increase in left ventricular mass index (LVMI),inferior vena cava (IVC) diameter and significantly higher decrease in ejection fraction more than low IDWG group I. Conclusions Patients with high IDWG group II at higher risk of increase LVMI, decrease ejection fraction, increase in interventricular septum (IVS), increase in inferior vena cava diameter more than patients of low IDWG group I and has more cardiovascular morbidity and mortality.

Myocardial performance and collateral flow after transient coronary occlusion in exercising dogs

1979 ◽  
Vol 237 (4) ◽  
pp. H520-H527
Author(s):  
M. V. Cohen ◽  
T. Yipintsoi
Keyword(s):  
Stroke Volume ◽  
Left Atrial ◽  
Exercise Group ◽  
Left Ventricular ◽  
Treadmill Running ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Collateral Flow ◽  
Group I ◽  
Group Ii

Fourteen dogs with prior constriction of the left circumflex (LCf) coronary artery were studied at rest and during treadmill running. Hemodynamics were measured before and after a 1-min LCf occlusion. Coronary and collateral flows were quantitated during occlusion both at rest and during exercise. Group I consisted of 4 dogs with resting collateral flow exceeding one-half (average 78%) of normal flow, and group II consisted of 10 dogs with collateral flows less than one-half (average 30%) of normal. At rest LCf occlusion caused no hemodynamic changes in group I, but stroke volume fell significantly in group II. During running, collateral flow after LCf occlusion doubled in group I, and there was only a small rise in left atrial pressure to 18 mmHg. In group II, collateral flow increased by 50% during running and actually decreased in 4 dogs. Significant cardiac failure developed as stroke volume halved, and left atrial pressure rose to an average 30 mmHg. Therefore exercise-induced depression of left ventricular function in the ischemic heart can be correlated to the amount of coronary collateral flow.

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