322
slcru . .+lA l'V .5511)1( 1'1)5111
NIrAI a FART DISI`ASP. l)XY(a1N UP-FAKE AND VLNTIIAfl0N
cessive linvnolysis and heparininduced defects. Bleeding in these potions should he treated with replacement therapy . which in most cases is limited to platelets and fresh frozen plasma . Dcsmopressin has been found to be helpful in reducing the hlneding after open heart surgery and may increase von Willebrand 1'uctor concentrations in these patients (13) .
References I . LinJerhaml, o. Klu,e Hl. Belke K, e; ul, fir--d blood vian •i q n pal-l, . .fl, clanau< nmgCndul laud I,,dnC and ron deheeney . , vedmlr I974 ;95 :56' u. 2 . go ,uceslil.I'Mu JK .HookingWG,Child15,(loohhioNINLSki"',
W . Ch n,( hrpnwenlia and dncamprn,aled Cpdhmcyln,l, 1n ascnnIn, tnngemlul hear) dnea,e . LanCel 1966^_911-4. 1. Pert-T IK . knave Mil . Child 1S . Wnghr GP Adnhs nih Gy+nmlc canonndaI hear) daoae- hemaAlng,c nlallagemenl . Ann ha- Wit .406-I3 .11 19N14 4.
Than,, Dl, SIarshall 1 . an „ell IM . eI al . LOne) of herraarcril on cemhral hlwngdon m man . Canon! 1977 ;• 941-1.
JAI Val. in . 5,, 2 Au,- 1991111-42
Gurdnm RS Jr . Kahn H .A. Po,me S . A5111J0 ant ITiVD death r :an chin ipparCnt rtlmon+hlp Ilpnrrl. S)mke 1977 .1 227J. 6. F'riedlund RP. Hcmarcnl . -rvum!) . and eercbral Mood flak . Am Heart 1 1979 .97 41M-5 . 7. Hennkwon P. Valendh G, Lund+arum NR . llaemoon, detect, Ia aynnoan, conten111 heard du,,- Rr Mean 1197Y:41'21-7 . N. Colon-0,er7 G, tillchd,l (is Hnleomt OR, Clomp DM, Map r1 . 5
DYaperntn't e,ciualinn nr hema,la'a, in pan-, wah eongenlai hear!
dl+Case. NJaIn Clin Proc 1967 ;6? ;179-N5. 9 . .Run H, (alehne) G5, Station R . Hamnmnd D, Hemuea,is in cyannu: a,narmdl heap di,eme . J Pedialr 1971;76 :111-11. il). WedemcserAL.kasatJR .KovilW,Coagulation incymnalicuongenli+i hear) A,ea,e . Am J la, Child 1977 17J:65G_l,. II. Ldmufld, LH, Nare,h CS . Hellyer P . Wilson TL Relminn,hir helueen platelet .all and cardiulani ,union remrn- Ann "florae Surg 1976 ;;1. 1:.
Sulamn A, Huga E thanoch D. et a1 . Deposition or terminal C2.4 nmplcmm,l rnmpkce, on enlhmryie, :md kukugne, du-,-1 ,np,d-
mnnlnV bypasr . N Engl I Vied 1966'.316 ;406-H. Il . N'am)ar. M, Wane JA. roll 1, Saltmun L . C han0a, m Inn 5Vdlchrnnd faemr dome cardiac mgerv either of 1--pr-in ace law . bind IsNN 71 :I6aH-55.
Cyanotic Congenital Heart Disease : Dynamics of Oxygen Uptake and Ventilation During Exercise KATHY E . SIETSEfnIA, MD
The matching oxygen and carbon dioxide exchange between the lungs and atmosphere in the rare of utilization and production of these gases by cellular metabolism is accomplished by tightly integrated circulatory and ventilatory function . Intracardcuc shunts allow left- and right-sided cardiac output to change unequally, resulting in "uncoupling" of the otherwise closely coupled processrs of external and internal So, uschange . Exercise testing with measurement of gas exchange provides valuable information about the physiologic significance of cyanotic and acyanotic congenital lesions and about the functional capabilities Of patients . Oxygen uptake in ccauotic congenital heart disease . Oxygen uptake IVO,i normally reaches a steady state level within 2 to 3 min after the onset of moderate exercise (I). The dynamic increase in VO, can he divided into two components the brief (10 to 20 sl rapid increase at exercise onset (phase 1), followed by an exponential increase (phase II) to the steady state . The cumulative difference between the oxygen cost of the exercise and VO, during the nonsteady state is the "oxygen deficit," which reflects work performed with use of preformed sources of high energy phosphates . nonoxidative pathways of metabolism and depletion of local oxygen stores (2) . The pattern of increase in ventilation (VE) is similar, although slightly slower than that of VO, . Distortion of these responses occurs in patients with cyanotic congenital heart disease, reflecting altered physiologic relations as a result of right to left shunting (3 .4) .
Because VU, is measured from respired gases, its immediate determinants are pulmonary blood flow and the arteriovenous difference in oxygen content (cla-v]00 across the pulmonary circulation IFick relation) : VO, = Q x c(a-v)0, . Normally, VO, doubles or triples relative to levels at rest during phase 1 (1,3) . reflecting an abrupt increase in pulmonary blond flow (3) . However, with cyanotic congenital heart disease, there may be lisle or no increase in VO_ in phase I and the attainment of a steady state is delayed (3). These findings undoubtedly reflect the effects of pulmonary blood flow and impaired ability to widen the arleriovenous difference in oxygen content due to progressively decreasing systemic arterial oxygen conten . Similarly . prolonged recovery times for return of VO, to rest levels have been reported 161 in children with cyanotic heart disease . Slow adaptation to changes in metabolic rate dictates that cyanotic patients spend a great deal of time in nonsleady states, depleting and replehng oxygen and high energy phosphate stores . It is likely that this derangement imposes an abnormal dependence on nonoxidative metabolism . Consistent with this assumption, lactic acidosis develops at lower levels of exercise in cyanotic patients than in normal subjects 17 .81 and muscle lactate levels are reported (9) to be higher in patients with tetralogy of Fallot than in normal subjects during maximal exercise . Blood lactate levels may underestimate the degree of tissue acidosis in cyanotic
JACC Vol 19, No . 2 mewl I9YIJ11-S
WEBB AND BURROWS RLSKS OF NONCARai, r SURGERY
patients . suggesting either enhanced lactate metabolism or
"Fable 1 . Ability Index
impaired washout of lactate from the n»ues 191_
I . Normal ldr Elull l Ime work or school .
Carbon dioxide clearance and ventila!lon . Clearance at
fO nd use atomic prep- 1 .
carbon dioxide is mediated by mechanisms controlling VE . ' and normally results in regulation of arterial partial pressure
(10) .
With a right to left shunt, venous carhop
dioxide is added directly to the arterial circulation . Despise this . rest Paco, is usually law because of high levels o€ VF 14,7 .01, During exercise, the Pco_ of venous (stood inceasel a result of increased production
•
Able
Dependant Ahem, 1 u,ehrmnd" 5,a ty imp-l- because orc .drae ceoni.ly .
s,,.
and the increased right to left shunt fraction . Increased
temic circulation
sation
-rk
tamaaaun all anwtues . Argnam . mh. i I-al2mrl~maarnn .
additional carbon d,-
We resulting from the buffering of lactic acid by bic rbvnate
amounts of carbon dioxide arc thus shunted into the st
1,
Imermdwnl syinnion, lriartearnve ban he .' Pmpnanp pu„ibls . i . I :nahlri, sod
ofcarbondioxide IPc'o,l and pH within narrow limits during exercise
321
nd .Pnd
-
To compensate for this and present CIo-
tinnnJJ
,in permission ram Wares CA . Burl J . Tricuspid
I, a dulrecems and adulu : current run and Ins mmpli~ Finns . Br 11I sf,-sly-i3 .
or pal the pulmonary capillary blood Pco, must be References
reduced to very low levels by hyperventilation . .Accordingly-
VE increases more in patients with a right to 1-ft shunt than for normal subjects at flue same exercise woik rate
Because the relation
tar.
or alveolar ventilation to pulmonary
capillary Pco, is hyperbolic . successive decrements in pulmonary capillary Pro, require progres,ively greater lucrements in VF, making compensation far carbon di redo
shunting physiologically difficult, it
Is therefore
I . Whirl , 11 .ShardSO.LamannaN,rial Paranoloaufvcmilamr>urntuse avhanpeJgnanawduringcsOioie .JApptPhr.iii 19X2 :Sn_:ISIM-Ii .
not surpris-
ing that cyanotic patients tend to develop respiratory woe II as metabolic acidosis during exercise [7.11). Summary. The presence of intracardicc shunts dissociates the right and left circulation . making dynamic coupling of cellular and pulmonary' got exchange :neff.ierl or impossible . As a result. patients may have profound changes in arterial blood gases and prolongation of adepht(ion and recovery even with low levels of physical act ity . Because the exercise-induced symptoms in patients wilb cyanotic congenital heart disease have bases apart from heart failure, assignment of a New York heart Aasocia-
PAs., .nprrn PF . Fnrrgctin of mlncut,, n erci, . Rev Physinl Riaehcm Ptarma,ul ma] :09 .143-:22.. Si ns. ma l Cnnper DM. Paths 1K . el al . Dynaaiesof oxygen uptake during ecerdcn in adults xith c! -spool congenital heart disease . Circula. ton 19%' ,3 :1137-iii Srenema KF . Cooper DST. Perlott. Ii, at . Corner of ventilation during m patient c e ntaeenral renou+tn systemic anenal shunts . J Appi Piruns, 196R:fiiIsa-i-
s cc, n,dn M I. . Jon,, Pw. oren A . et al . Cardiac nruput increase and rot r, .hmge :n Re star Id -re-, J A'rpl Pliant 19X`51 136-44 . fi . Orekunakn AC. Hall KH Me- c um ption dunes recovery o-n r. ets dren ssim r eaperpalhewn dd .- Am Jm.Cnild 147,1`s`6 .t-r Das , HH . Caretopaulos N . Dvspraea in iconic hewn disease . Br Itcart 1 " . 27:2-1 . x Enk,son BO . Blade B . Oygen uprlke arterial blood! eases and blood enlreuon during auhmanomal and manmut exercise in adult Iu: ,uhlerls a,In •. hunt-operaitd tstralngy cr Fatten Mid Med Sand 1975; 1'C t(t_9s . v tbasinB .E, l kvonBO.SahinB.ATP .C F.andlaaateeorcenuatwnsrn sde li .we duringex r Iv paen rim with tetralogy of Fallat . Sand J L'lin Lab Imet) l9 4 :34 :2u5 ni)
tton functional class may he misleading if not erroneous III Dr. lane Somerville recommends the `Ahiluc Index" show a in Table I .
w.inns
i K . ibtripp lit Catch_PO .pc,plratrayconicaldonut excra,, . 1o- I I .n,lhrnk nr Physinir~py: The Re .prrarnry System--Unmml nk liraihni 3'01 .= . Belhesl, MD: American Phyaolugt Society . 19X6 :595-619 .
The Risks of Noncardiac Surgery GARY D- WFBf3 . MD, F .ACC FREDERICK A . BURROWS, MID, FRCP
Adults with repaired . palliated or unoperimd r inpenital
hypenensinn . Perioperativa risk, can he reduced, often
heart disease may require noacardiac vugeery IFig II, but
significantly . when the problems inherent in this patient
there are relatively few published
population are anticipated . The functional status of the
:ports to glide their
management [ 11 . It is important l, underscore that manage-
patient remains an important consideration, but assignment
meet must take into consideration not only congenital heart
of risk based on New York Heart Association functional
disease itself. but also the cardiac and vascular diseases
class is often erroneous in cyanotic congenital heart disease
acquired with age, especialls coronary artery disease and
Isec Cyanotic Congenital Heart Disease Dynamics of Oxy-
slcru . .+lA l'V .5511)1( 1'1)5111
NIrAI a FART DISI`ASP. l)XY(a1N UP-FAKE AND VLNTIIAfl0N
cessive linvnolysis and heparininduced defects. Bleeding in these potions should he treated with replacement therapy . which in most cases is limited to platelets and fresh frozen plasma . Dcsmopressin has been found to be helpful in reducing the hlneding after open heart surgery and may increase von Willebrand 1'uctor concentrations in these patients (13) .
References I . LinJerhaml, o. Klu,e Hl. Belke K, e; ul, fir--d blood vian •i q n pal-l, . .fl, clanau< nmgCndul laud I,,dnC and ron deheeney . , vedmlr I974 ;95 :56' u. 2 . go ,uceslil.I'Mu JK .HookingWG,Child15,(loohhioNINLSki"',
W . Ch n,( hrpnwenlia and dncamprn,aled Cpdhmcyln,l, 1n ascnnIn, tnngemlul hear) dnea,e . LanCel 1966^_911-4. 1. Pert-T IK . knave Mil . Child 1S . Wnghr GP Adnhs nih Gy+nmlc canonndaI hear) daoae- hemaAlng,c nlallagemenl . Ann ha- Wit .406-I3 .11 19N14 4.
Than,, Dl, SIarshall 1 . an „ell IM . eI al . LOne) of herraarcril on cemhral hlwngdon m man . Canon! 1977 ;• 941-1.
JAI Val. in . 5,, 2 Au,- 1991111-42
Gurdnm RS Jr . Kahn H .A. Po,me S . A5111J0 ant ITiVD death r :an chin ipparCnt rtlmon+hlp Ilpnrrl. S)mke 1977 .1 227J. 6. F'riedlund RP. Hcmarcnl . -rvum!) . and eercbral Mood flak . Am Heart 1 1979 .97 41M-5 . 7. Hennkwon P. Valendh G, Lund+arum NR . llaemoon, detect, Ia aynnoan, conten111 heard du,,- Rr Mean 1197Y:41'21-7 . N. Colon-0,er7 G, tillchd,l (is Hnleomt OR, Clomp DM, Map r1 . 5
DYaperntn't e,ciualinn nr hema,la'a, in pan-, wah eongenlai hear!
dl+Case. NJaIn Clin Proc 1967 ;6? ;179-N5. 9 . .Run H, (alehne) G5, Station R . Hamnmnd D, Hemuea,is in cyannu: a,narmdl heap di,eme . J Pedialr 1971;76 :111-11. il). WedemcserAL.kasatJR .KovilW,Coagulation incymnalicuongenli+i hear) A,ea,e . Am J la, Child 1977 17J:65G_l,. II. Ldmufld, LH, Nare,h CS . Hellyer P . Wilson TL Relminn,hir helueen platelet .all and cardiulani ,union remrn- Ann "florae Surg 1976 ;;1. 1:.
Sulamn A, Huga E thanoch D. et a1 . Deposition or terminal C2.4 nmplcmm,l rnmpkce, on enlhmryie, :md kukugne, du-,-1 ,np,d-
mnnlnV bypasr . N Engl I Vied 1966'.316 ;406-H. Il . N'am)ar. M, Wane JA. roll 1, Saltmun L . C han0a, m Inn 5Vdlchrnnd faemr dome cardiac mgerv either of 1--pr-in ace law . bind IsNN 71 :I6aH-55.
Cyanotic Congenital Heart Disease : Dynamics of Oxygen Uptake and Ventilation During Exercise KATHY E . SIETSEfnIA, MD
The matching oxygen and carbon dioxide exchange between the lungs and atmosphere in the rare of utilization and production of these gases by cellular metabolism is accomplished by tightly integrated circulatory and ventilatory function . Intracardcuc shunts allow left- and right-sided cardiac output to change unequally, resulting in "uncoupling" of the otherwise closely coupled processrs of external and internal So, uschange . Exercise testing with measurement of gas exchange provides valuable information about the physiologic significance of cyanotic and acyanotic congenital lesions and about the functional capabilities Of patients . Oxygen uptake in ccauotic congenital heart disease . Oxygen uptake IVO,i normally reaches a steady state level within 2 to 3 min after the onset of moderate exercise (I). The dynamic increase in VO, can he divided into two components the brief (10 to 20 sl rapid increase at exercise onset (phase 1), followed by an exponential increase (phase II) to the steady state . The cumulative difference between the oxygen cost of the exercise and VO, during the nonsteady state is the "oxygen deficit," which reflects work performed with use of preformed sources of high energy phosphates . nonoxidative pathways of metabolism and depletion of local oxygen stores (2) . The pattern of increase in ventilation (VE) is similar, although slightly slower than that of VO, . Distortion of these responses occurs in patients with cyanotic congenital heart disease, reflecting altered physiologic relations as a result of right to left shunting (3 .4) .
Because VU, is measured from respired gases, its immediate determinants are pulmonary blood flow and the arteriovenous difference in oxygen content (cla-v]00 across the pulmonary circulation IFick relation) : VO, = Q x c(a-v)0, . Normally, VO, doubles or triples relative to levels at rest during phase 1 (1,3) . reflecting an abrupt increase in pulmonary blond flow (3) . However, with cyanotic congenital heart disease, there may be lisle or no increase in VO_ in phase I and the attainment of a steady state is delayed (3). These findings undoubtedly reflect the effects of pulmonary blood flow and impaired ability to widen the arleriovenous difference in oxygen content due to progressively decreasing systemic arterial oxygen conten . Similarly . prolonged recovery times for return of VO, to rest levels have been reported 161 in children with cyanotic heart disease . Slow adaptation to changes in metabolic rate dictates that cyanotic patients spend a great deal of time in nonsleady states, depleting and replehng oxygen and high energy phosphate stores . It is likely that this derangement imposes an abnormal dependence on nonoxidative metabolism . Consistent with this assumption, lactic acidosis develops at lower levels of exercise in cyanotic patients than in normal subjects 17 .81 and muscle lactate levels are reported (9) to be higher in patients with tetralogy of Fallot than in normal subjects during maximal exercise . Blood lactate levels may underestimate the degree of tissue acidosis in cyanotic
JACC Vol 19, No . 2 mewl I9YIJ11-S
WEBB AND BURROWS RLSKS OF NONCARai, r SURGERY
patients . suggesting either enhanced lactate metabolism or
"Fable 1 . Ability Index
impaired washout of lactate from the n»ues 191_
I . Normal ldr Elull l Ime work or school .
Carbon dioxide clearance and ventila!lon . Clearance at
fO nd use atomic prep- 1 .
carbon dioxide is mediated by mechanisms controlling VE . ' and normally results in regulation of arterial partial pressure
(10) .
With a right to left shunt, venous carhop
dioxide is added directly to the arterial circulation . Despise this . rest Paco, is usually law because of high levels o€ VF 14,7 .01, During exercise, the Pco_ of venous (stood inceasel a result of increased production
•
Able
Dependant Ahem, 1 u,ehrmnd" 5,a ty imp-l- because orc .drae ceoni.ly .
s,,.
and the increased right to left shunt fraction . Increased
temic circulation
sation
-rk
tamaaaun all anwtues . Argnam . mh. i I-al2mrl~maarnn .
additional carbon d,-
We resulting from the buffering of lactic acid by bic rbvnate
amounts of carbon dioxide arc thus shunted into the st
1,
Imermdwnl syinnion, lriartearnve ban he .' Pmpnanp pu„ibls . i . I :nahlri, sod
ofcarbondioxide IPc'o,l and pH within narrow limits during exercise
321
nd .Pnd
-
To compensate for this and present CIo-
tinnnJJ
,in permission ram Wares CA . Burl J . Tricuspid
I, a dulrecems and adulu : current run and Ins mmpli~ Finns . Br 11I sf,-sly-i3 .
or pal the pulmonary capillary blood Pco, must be References
reduced to very low levels by hyperventilation . .Accordingly-
VE increases more in patients with a right to 1-ft shunt than for normal subjects at flue same exercise woik rate
Because the relation
tar.
or alveolar ventilation to pulmonary
capillary Pco, is hyperbolic . successive decrements in pulmonary capillary Pro, require progres,ively greater lucrements in VF, making compensation far carbon di redo
shunting physiologically difficult, it
Is therefore
I . Whirl , 11 .ShardSO.LamannaN,rial Paranoloaufvcmilamr>urntuse avhanpeJgnanawduringcsOioie .JApptPhr.iii 19X2 :Sn_:ISIM-Ii .
not surpris-
ing that cyanotic patients tend to develop respiratory woe II as metabolic acidosis during exercise [7.11). Summary. The presence of intracardicc shunts dissociates the right and left circulation . making dynamic coupling of cellular and pulmonary' got exchange :neff.ierl or impossible . As a result. patients may have profound changes in arterial blood gases and prolongation of adepht(ion and recovery even with low levels of physical act ity . Because the exercise-induced symptoms in patients wilb cyanotic congenital heart disease have bases apart from heart failure, assignment of a New York heart Aasocia-
PAs., .nprrn PF . Fnrrgctin of mlncut,, n erci, . Rev Physinl Riaehcm Ptarma,ul ma] :09 .143-:22.. Si ns. ma l Cnnper DM. Paths 1K . el al . Dynaaiesof oxygen uptake during ecerdcn in adults xith c! -spool congenital heart disease . Circula. ton 19%' ,3 :1137-iii Srenema KF . Cooper DST. Perlott. Ii, at . Corner of ventilation during m patient c e ntaeenral renou+tn systemic anenal shunts . J Appi Piruns, 196R:fiiIsa-i-
s cc, n,dn M I. . Jon,, Pw. oren A . et al . Cardiac nruput increase and rot r, .hmge :n Re star Id -re-, J A'rpl Pliant 19X`51 136-44 . fi . Orekunakn AC. Hall KH Me- c um ption dunes recovery o-n r. ets dren ssim r eaperpalhewn dd .- Am Jm.Cnild 147,1`s`6 .t-r Das , HH . Caretopaulos N . Dvspraea in iconic hewn disease . Br Itcart 1 " . 27:2-1 . x Enk,son BO . Blade B . Oygen uprlke arterial blood! eases and blood enlreuon during auhmanomal and manmut exercise in adult Iu: ,uhlerls a,In •. hunt-operaitd tstralngy cr Fatten Mid Med Sand 1975; 1'C t(t_9s . v tbasinB .E, l kvonBO.SahinB.ATP .C F.andlaaateeorcenuatwnsrn sde li .we duringex r Iv paen rim with tetralogy of Fallat . Sand J L'lin Lab Imet) l9 4 :34 :2u5 ni)
tton functional class may he misleading if not erroneous III Dr. lane Somerville recommends the `Ahiluc Index" show a in Table I .
w.inns
i K . ibtripp lit Catch_PO .pc,plratrayconicaldonut excra,, . 1o- I I .n,lhrnk nr Physinir~py: The Re .prrarnry System--Unmml nk liraihni 3'01 .= . Belhesl, MD: American Phyaolugt Society . 19X6 :595-619 .
The Risks of Noncardiac Surgery GARY D- WFBf3 . MD, F .ACC FREDERICK A . BURROWS, MID, FRCP
Adults with repaired . palliated or unoperimd r inpenital
hypenensinn . Perioperativa risk, can he reduced, often
heart disease may require noacardiac vugeery IFig II, but
significantly . when the problems inherent in this patient
there are relatively few published
population are anticipated . The functional status of the
:ports to glide their
management [ 11 . It is important l, underscore that manage-
patient remains an important consideration, but assignment
meet must take into consideration not only congenital heart
of risk based on New York Heart Association functional
disease itself. but also the cardiac and vascular diseases
class is often erroneous in cyanotic congenital heart disease
acquired with age, especialls coronary artery disease and
Isec Cyanotic Congenital Heart Disease Dynamics of Oxy-
