-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
1/21
Thyroid and CardiovascularProblem s
Roy Christian
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
2/21
The cardiovascular signs and symptomsof thyroid disease are some of the mostprofound and clinically relevant ndingsthat accompany both hyperthyroidism
and hypothyroidism Both hyperthyroidism and hypothyroidism
produce changes in cardiac contractility,myocardial oxygen consumption, cardiacoutput, blood pressure, and systemicvascular resistance (SVR
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
3/21
!lthough it is "ell #no"n thathyperthyroidism can produce atrialbrillation, it is less "ell recogni$edthat hypothyroidism can predispose toventricular dysrhythmias%
&n almost all cases these
cardiovascular changes are reversible"hen the underlying thyroid disorderis recogni$ed and treated
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
4/21
Thyroid disease is 'uite common%
Current estimates suggest that it
aects as many as )* to +* of theadult female population and asmaller percentage of adult males%
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
5/21
Cellular M echanism s ofThyroid H orm one Action
T- and T. are synthesi$ed by the thyroidgland in response to TS/%
The thyroid gland primarily secretes T-
(0*, "hich is converted to T. by 1monodeiodination in the liver, #idney, ands#eletal muscle%
The heart relies mainly on serum T.
because no signicant myocyte intracellulardeiodinase activity ta#es place, and itappears that T., and not T-, is transportedinto the myocyte
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
6/21
BRAUNW ALD’S HARTD!SAS
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
7/21
Ef fects of Thyroid H orm oneon CardiovascularH em odynam ics Thyroid hormone eects on the heart
and peripheral vasculature
include decreased SVR and increasedresting heart rate, left ventricularcontractility, and blood volume
Thyroid hormone causes decreased
resistance in peripheral arteriolesthrough a direct eect on VS2 anddecreased mean arterial pressure
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
8/21
!ctivates the renin1angiotensin1aldosterone system and increasesrenal sodium absorption%
T. also increases erythropoietinsynthesis, "hich leads to an increasein red cell mass
Promote an increase in bloodvolume and preload%
Ef fects of Thyroid H orm oneon CardiovascularH em odynam ics
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
9/21
Braun"ald’s hear# disease
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
10/21
3iastolic function, as measured by the isovolumic relaxationtime, varies over the entire range of thyroid disease, includingovert hypothyroidism (4/, subclinical hypothyroidism (SC/,control (C, hyperthyroidism (/, hyperthyroidism after beta1
adrenergic bloc#ade (/ 5 6, and hyperthyroidism aftertreatment to restore normal thyroid function (7
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
11/21
H yperthyroidism
6atients "ith hyperthyroidismpresent "ith characteristic signs andsymptoms, many related to the heartand cardiovascular system%
/yperthyroidism8 increasedformation and release of thyroid
hormones from the thyroid gland Thyrotoxicosis8 the clinical syndrome
that results from thyroid hormone
excess
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
12/21
Cardiovascular Signs and Symptoms ofHyperthyroidism
6alpitations
!nginal chest pain
7xercise intolerance
!trial brillation
7xertional dyspnea
Cardiac hypertrophy
Systolic hypertension 6eripheral edema
/yperdynamic precordium
Congestive heart failure
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
13/21
ATR!AL $!BR!LLAT!%N
The most common rhythm disturbancein patients "ith hyperthyroidism is sinustachycardia, but its clinical impact is
overshado"ed by patients "ith atrialbrillation resulting from thyrotoxicosis
Treatment of atrial brillation in the
setting of hyperthyroidism includesbeta1adrenergic bloc#ade to control theventricular response
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
14/21
!nticoagulation of patients "ithhyperthyroidism and atrial brillationis controversial%
The ris# of systemic or cerebralemboli$ation must be "eighedagainst the potential for bleeding
and other complications of thistherapy
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
15/21
H eart Failure
6atients "ith hyperthyroidism may havesigns and symptoms indicative of heartfailure
6atients "ith both severe and chronic
hyperthyroidism, exaggerated sinustachycardia or atrial brillation can producerate1related left ventricular dysfunction andheart failure
6reexistent ischemic or hypertensive heartdisease may also predispose thehyperthyroid patient to the development ofheart failure
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
16/21
H ypothyroidism
The most common cardiovascularsigns and symptoms ofhypothyroidism are diametricallyopposed to those described forhyperthyroidism and may includebradycardia, mild hypertension
(diastolic, narro"ed pulse pressure,cold intolerance, and fatigue
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
17/21
Cardiovascular Risks
Associated W ithH ypothyroidism &mpaired cardiac contractility anddiastolic function
&ncreased systemic vascularresistance 3ecreased endothelial1derived relaxation
factor
&ncreased serum cholesterol &ncreased C1reactive protein
&ncreased homocysteine
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
18/21
The treatment of hypothyroidism in thesetting of #no"n or suspected cardiacdisease poses some challenges% &n
young,other"ise healthy patients "ithovert hypothyroidism, treatment "ith a fullreplacement dose of 91thyroxine (9evoxyl,Synthroid of +%: g;#g per d can be initiated
&n older patients, the adage of start lo" (
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
19/21
M yxedem a Com a
The most severe form of hypothyroidismis that associated "ith profound C>Sdepression
and is called myxedema coma
the term only refers to patients in comaascribed to hypothyroidism
!ny of the signs and symptoms ofhypothyroidism may be present inmyxedema coma, but signi cantdepression of the sensorium is re'uired
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
20/21
!ny of the signs and symptoms ofhypothyroidism may be present in myxedemacoma, but signi cant depression of thesensorium is re'uired
2yxedema coma is treated "ith thyroid hormone
replacement% 9oading dose of .== g of thyroxine&V, follo"ed by daily doses of = to +== g &V%
/ydrocortisone, .== mg;d &V in divided doses, isadministered empirically for possible coexisting
adrenal insu? ciency% !s an alternative to givinghydrocortisone, a single dose of dexamethasonemay be administered "hile the rapid cosyntropinstimulation test is performed% 4nce the test iscompleted, hydrocortisone is initiated%
-
8/20/2019 Thyroid and Cardiovascular Problems ( Dr. Roy Christian, SpJ
21/21
Thank you