Journal of Experimental Medical & Surgical Research

Cercetãri Experimentale & Medico-Chirurgicale JOURNAL of

Experimental
Year XVIII · Nr.1/2011 · Pag. 5 -8
Medical Surgical
R E S E A R C H

INCIDENCE OF PULMONARY HYPERTENSION IN

HYPERTHYROID PATIENTS
Cristina Tudoran1, SUMMARY: A frequent association between pulmonary hypertension (PTH) and
Mariana Tudoran1, hyperthyroidism has been observed in the last years, especially in patients with Graves
Rodica Avram1, Basedow disease. The etiology of PTH has multiple pathophysiological determinants: high
Melania Balaº2, output state, autoimune factors, and absence of decreased vascular resistance in the
pulmonar arterial bed. We determined the incidence of PTH in a group of 41 patients with
Mihaela Vlad2,
hyperthyroidism of different etiologies, using M mode, 2D, Doppler and Collor Doppler
Ioana Zosin2 echocardiographic technics.
Keywords: pulmonary hypertension, hyperthyroidism, echocardiography.

INCIDENÞA HIPERTENSIUNII PULMONARE LA PACIENÞII CU HIPERTIROIDIE

Rezumat: În ultimii ani a fost observatã o asociere frecventã între hipertensiunea pulmonarã
(HTP) ºi hipertiroidie, în special la pacienþii cu boalã Graves Basedow. Etiologia HTP este
din punct de vedere fiziopatologic, multifactorialã: sindromul de debit cardiac crescut,
factori autoimuni ºi absenþa rãspunsului vasodilatator la nivelul patului vascular pulmonar.
Received for publication: 06.12.2010 Am determinat incidenþa HTP într-un grup de 41 pacienþi hipertiroidieni, cu diferite etiologii,
Revised: 08.01.2011 utilizând tehnici ecocardiografice M mode, 2 D, Doppler ºi Doppler color.
Cuvinte cheie: hipertensiune pulmonarã, hipertiroidism, ecocardiografie.

1. - Clinic of Cardiology, University of Medicine and Pharmacy, Timiºoara

2. - Clinic of Endocrinology, University of Medicine and Pharmacy, Timiºoara

INTRODUCTION dilatation of tricuspid annulus. In patients with

Graves-Basedow disease an autoimmune process and
A high prevalence of PTH (about 40-70%) has been
the presence of associated endothelial damage seem to
documented in hyperthyroid patients in the last decade.
be the most plausible cause. Other autors suggested that
The most frequent etiologies of hyperthyroidism are
the effect of thyroid hormone to decrease sistemic
Graves Basedow disease, toxic adenoma and
vascular resistance (SVR) may not occur in the
polynodular goitre. Using the World Health Organization’s
pulmonary vasculature.
criteria, pulmonary arterial hypertension is defined by a
Pulmonary arterial hypertension is characterized by a
pulmonary artery pressure (PAP)$ 25 mm Hg at rest,
sustained increase in pulmonary arterial pressure and a
with normal values under 20 mmHg. The significance of a
progressive increase in pulmonary vascular resistance,
mean PAP between 21 and 24 mmHg is unclear.
that leads to right ventricular failure and premature death.
The pathophysiological mechanisms of PTH and
We must mention that PTH can be induced also by
tricuspid regurgitation or even right heart failure in
pulmonary ilnesses, like asthma, chronic bronchitis and
thyrotoxicosis are not completely understood.
COPD.
Hyperthyroidism leads to a hyperkinetic state, most often
associated with high cardiac output due to increased AIM OF THE STUDY
heart rate and inotropism and with elevated circulatory
volume. High cardiac output combined with increased The aim of this paper was to establish the incidence of
circulatory volume determine an increased and rapid PTH in our study group and if there exists any association
venous return to the right ventricle. This factors increase between PTH and the severity and evolution of
pulmonary arterial pressure and dilate the right ventricle. hyperthyroidism.
Tricuspid regurgitation can occurre as a result of the
Correspondence to: Dr. Cristina Tudoran, e-mail: cris_tudoran@yahoo.com

5
 dimensions of the heart cavities, left ventricular function,
MATERIAL AND METHOD presence and severity of valvular disfunctions and we
The study group consisted of 41 patients, 3 men and tried to establish the presence and severity of the
38 women, aged between 23 and 70 years (mean tricuspide regurgitation and of the pulmonary
age=47"6 years), admitted in the Clinic of Endocrinilogy hypertension. In most of the cases, we used the velocity
of the County Hospital Timisoara in the period oct. 2009 - of the tricuspid regurgitated jet to estimate right
feb. 2011. 39 subiects had overt and 2 subclinical ventricular end systolic pressure via the Bernoulli
hyperthyroidism of various etiology, mainly equation (4v2, where v is the maximum velocity of the
Graves-Basedow disease. tricuspid valve regurgitated jet). In selected patients, we
All patients had first an endocrinologic examination, tried to visualise the pulmonary artery (PA) and to
which consisted of hormonal determinations (TSH, FT4, determine the flow velocity of the regurgitated jet using
FT3), imunological ones (LATS, TPO-Abs) and Pulsed Doppler measurement.
sonography, in order to establish the etiology and
RESULTS AND DISCUSSIONS:
severity of the thyroid disorder. Subsequently, they
where evaluated by the cardiologist: history, physical The etiology of hyperthyroidism in the study group
examination, ECG, chest x-ray and echocardiography was represented, in most of the cases, by
done with an Acuson Sequoia C512 echocardiograph. At Graves-Basedow disease (33 patients, 80.48%), toxic
the echocardiographic examination, we assesed the adenoma (3 cases, 7.31%), polynodular goitre (4
patients, 9.75%) and 1 subject (2.43%) had subacute
9.75% 2.43% thyroiditis, as presented in fig.1. Among the patients
7,31%
with Graves Basedow disease, 11 patient had newly
diagnosed forms (6 with severe thyrotoxicosis and 5
moderate ones) and 22 patients had chronic disease,
lasting for more years.
80,48% We tried to identify other factors that could lead to
PTH like cardiovascular diseases with left ventricular
disfunction and respiratory disorders. After rigurous
clinical and laboratory examinations, we found in the
majority of the patients associated cardiovascular and
Graves Basedow disease
respiratory diseases, see table 1.
toxic adenoma
polynodular goitre
Most of the them had systemic hypertension (14
thyroiditis patients – 34.14%) grade I or II, 17 patients (41.46%) had
mitral and aortic valvular disfunctions, in the majority of
Fig.1. Etiology of hyperthyroidism in 41 patients. cases without haemodynamic consequences, and 4

Table 1. Results of laboratory examination

Associated diseases Patients with overt Patients with subclinical

hyperthyroidism 39 P hyperthyroidism 2 P

Systemic hypertension: gr I 5
1
gr II 8

Valvular disfunctions: mild 8 1

moderate 7 -
severe 1 -

Atrial fibrillation: paroxistic 2 -

persistent 1 -
permanent 1 -

Respiratory diseases: chronic bronchitis 11 1

asthma 1 -
COPD 1 -

6
Table 2. Results of echocardiographic examinations

Results of echocardiographic Patients with overt Patients with subclinical

Examination in 41 patients hyperthyroidism 39 P hyperthyroidism 2 P

Mitral/aortic regurgitation: 17 1 – 50%

Mild 12 1
Moderate 5 -
LV Hypertrophy 5 -
LV Hypokinesia 10 -
Reduced EF of LV 5 -
Diastolic dysfunction 3 -
Pulmonary hypertension:
Mild 10 1
Moderate 8 -
Severe 2 -
Tricuspid regurgitation: 20- 51,28% 1
RV Hypertrophy 12 -

patients (9.75%) had atrial fibrillation (2 paroxistic, 1 grade I or II did not seeem to increase the incidence of
persistent and 1 permanent). 14 (34.14%) patients had PTH and tricuspid regurgitation.
respiratory diseases: 1 asthma, 1 COPD and 11 chronic The degree of pulmonary hypertension and tricuspid
bronchitis, as shown in table 1. regurgitation does not strongly correlate with the severity
Only 11 patients had no comorbidities with exception of symptoms or survival, whereas dilatation of the right
of hyperthyroidism. However, it is important to mention ventricle and right atrial size reflect functional status and
that only few subjects had cardiovascular disorders are strong predictors of survival.
severe enough to cause left heart failure per se, and only However, there are conflicting data as to the strength
1 patient had moderate COPD that could lead to PTH. of the correlation between RV systolic pressure
The results of the echocardiographic examinations are estimated by Doppler echocardiography and mean
presented in table 2. Most of the patients had mild or pulmonary artery pressure (PAP) measured via right
moderate abnormalities, but 5 of them had impaired heart catheterization. When RV and PAP are estimated
ejection fraction (EF) of the left ventricle (LV). Only 9 via echocardiography, they more often are higher than
subjects had no pathological findings. the pressures measured directly by catheterization.
From the 41 patients with hyperthyroidism 21 had Degree of tricuspid regurgitation can be decreased as a
tricuspid regurgitation and pulmonary hypertension and result of decreased right ventricular pressure.
12 of them had enlarged right ventricle (RV). As our knowledge of RV physiology and biology
Hyperthyroidism is a cause of PTH with isolated increases, it is becoming apparent that a comprehensive
tricuspid regurgitation and right sided heart failure. approach to the RV, the pulmonary circulation, and their
Severity of PTH and grade of tricuspid regurgitation interactions will be beneficial in both clinical
corelate more with the lenght of the disease. The 2 management of PTH patients and clinical research. The
patients with severe PTH had long lasting Graves evolution of RV pathology from the normal to a
Basedow disease, with severe thyrotoxicosis and poorly compensated (hypertrophied) and then decompensated
therapeutic response to oral antithyroid drugs. They had state parallels the evolution of pulmonary vascular
persistent or permanent atrial fibrillation and right cardiac pathology from a vasodilated high-capacitance state to
failure. The 11 patients with recent diagnosed Graves vasoconstricted arteries and early loss of endothelial
Basedow disease had no PTH or mild forms. The same cells/capillaries to an end-stage proliferative and
aspect was found in treated patients with good clinical obliterative vascular remodeling. Therefore, it is
response and in the 2 patients with subclinical important to study the RV and the PAPs comprehensively
hyperthyroidism. Coexisting mild mitral and/or aortic and simultaneously as a unit.
regurgitation and the presence of systemic hypertension

7
 3. The degree of pulmonary hypertension does not
CONCLUSIONS strongly correlate with the severity of symptoms or
1. The etiology of PTH in hyperthyroidism has multiple survival;
patho-physiological determinants wich are not 4. Hyperthyroidism should be considered in the
completely understood; differential diagnosis of right-sided heart failure with
2. In patients with Graves Basedow disease, pulmonary hypertension.
hyperthyroidism is frequently associated with pulmonary
arterial hypertension due to autoimmune mechanisms;

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