Jerarquía de valores que manifiestan actualmente los

36 Protocol 3:

EVALUATION.

A 12 lead ECG and 24 Hour Holter electrocardiography were done on all subjects to evaluate the heart rhythm disturbances. Echocardiography was also carried out to evaluate the systolic and diastolic function as well as cardiac structures of both subjects and controls. Other laboratory investigations done included packed cell volume and serum electrolytes.

37

The ECG was analysed to obtain heart rate, rhythm, P wave morphology, QRS complexes, presence of left ^{110, 149} or right ventricular hypertrophy, and arrhythmias following the standard recommendations.^{147, 148}

24 Hour Holter ECG

A 24 hour ambulatory ECG was done using the Schiller type (MT-101) with a bipolar V1-V5 lead system. After a thorough explanation of the nature of the test and familiarization of the subjects with the recorder, each subject in turn had the recorder strapped on them with the channel leads firmly placed on the chest and allowed to go back home. Channel leads were placed conventionally.¹⁵⁰ During the recording, subjects were instructed to record timing of symptoms of palpitations, dizziness, chest pain and syncope in an event diary. After completion of the recording over a 24 hour period, the recorder was retrieved and analysed with Schiller’s cardiovit CS-200 digital ECG computer. The following data were recorded; heart rhythm, heart rate, heart rate variability (HRV) as well as the quality and quantity of the arrhythmias present¹³⁶ (Premature atrial complexes, ventricular ectopics, ventricular tachycardia, atrial flutter and atrial fibrillation).

Heart rate variability (HRV) was analysed using Standard deviation of all normal to normal sinus RR interval over 24 Hours. ¹⁵¹ The normal values of HRV (using standard deviation of normal to normal intervals average (milliseconds) SDNN) used for the study were in accordance with the ACC/AHA Guidelines for Ambulatory ECG, ¹²² was 141±39 milliseconds (ms).

Significant premature ventricular complexes (PVC) and premature atrial complexes (PACs) were defined as presence of PVC or PACs greater than 10% of the total QRS complexes and/or Lown grade 2 and above.

The Lown’s grading of PVC among patients with PVCs was applied as follows;

38 Grade Arrhythmia

0 No ventricular ectopics

1 Occasional isolated PVCs, < 30/hour.

2 Frequent PVCs, > 30/hour.

3 Multiform PVCs.

4a Repetitive PVCs (couplets).

4b Repetitive PVCs (Salvos), >3 consecutive PVCs.

5 R on T phenomenon.

Echocardiography

Echocardiography was done using a standard Vivid 7 Dimension ultrasound imaging system with the 5S transthoracic phased array sector probe for adults with transducer frequency of 2.2 - 5.0MHz made by General Electrics (GE) Medical Systems.

All the goiter subjects and the control had 2-Dimensional (2-D), 2-D guided M mode and Doppler (pulsed wave, continuous wave and colour flow) transthoracic echocardiography with simultaneous ECG recordings. Measurements were in accordance with the recommendation of the American Society of Echocardiography¹⁵² with the leading edge to leading edge

measurement taken, taking an average of three consecutive cycles measurements. The

echocardiographic findings that were determined using standard techniques include: systolic and diastolic function, valvular regurgitation, wall dimensions, chamber size, pericardial

abnormalities and pericardial effusion.

Left ventricular wall and chamber dimensions were measured using 2D-guided M-mode echocardiography with simultaneous electrocardiographic monitoring of the cardiac cycle. The M-mode cursor cut perpendicularly across the interventricular septum, left ventricular chamber and posterior wall at the level of the mitral valve tips as the cardiac anatomy was visualized with

39

the 2D echo from the parasternal long axis view. Measurements were made with leading edge to leading edge recordings taken end-diastole and end-systole. End-diastole was recognized as the beginning of the electrocardiographic qRs complex while end-systole was recognized as the peak downward deflection of the interventricular septum and the peak upward defection of the left ventricular posterior wall.

Left ventricular mass was derived using the Devereux modified American Society of Echocardiography (ASE) formula: ⁸⁵

Left ventricular mass (g) = 1.04[(LVIDd+PWTd+IVSd)³– (LVIDd)³] x 0.8 + 0.6g Where 1.04 = specific gravity of the myocardium

0.8 = correction factor

LVIDd = left ventricular internal diameter in diastole (in centimetres (cm)) PWTd = left ventricular posterior wall thickness in diastole (in cm)

IVSTd = interventricular septal thickness in diastole (in cm)

LV mass index was obtained from LV mass divided by body surface area. Upper limits for LV mass index were 134 and 110g/m² in men and women respectively. ^{153, 154}

Relative wall thickness (RWT) was calculated using the formula:

RWT = (IVSTd + PWTd) / LVIDd.

RWT value less than 0.45 is indicative of normal left ventricular geometry or eccentric hypertrophy while a value of 0.45 and above indicates concentric left ventricular hypertrophy or remodeling for both men and women. ¹⁵⁴

40

Where applicable, measurements were indexed for body surface area which was calculated with the Mosteller formula: ¹⁵⁵ Square root of [Weight (kg) x Height (cm) / 3600]

Left ventricular systolic function was assessed using two methods:

1. M-mode echocardiography taken from the parasternal long axis view to determine left ventricular ejection fraction (EF) and fractional shortening (FS). The Teicholz formula which had been programmed by the automated facilities in the echocardiography machine was used for determining the left ventricular volumes in diastole and end-systole:

7/(LVID +2.4) x LVID³. ⁸⁹

Where LVID= left ventricular internal dimension.

Ejection fraction was then determined by the formula: EF = LVEDV – LVESV X 100%

LVEDV Where LVEDV = left ventricular end-diastolic volume

LVESV = left ventricular end-systolic volume

Fractional shortening was determined by the formula: FS = LVIDd- LVIDs X 100%

LVIDd Where LVIDd = left ventricular internal diameter in diastole;

LVIDs = left ventricular internal diameter in systole.

The above formulae had been programmed by the automated facilities in the echocardiography machine.

Enhanced (meaning increased myocardial contractility) systolic function^{17, 156} was present if the ejection fraction was greater than 75% and fractional shortening greater than 42%.

Normal reference values for Ejection fraction and fractional shortening are 50-75% and 25-42% respectively.^17,152

Left ventricular systolic dysfunction was taken as ejection fraction less than 50%.

2. Tissue Doppler interrogation was performed with the sample volume taken at the septal and lateral sides of the mitral annulus to determine the systolic tissue velocity (s’).

41

There are no generally accepted reference values but different cut-off points ranging from 5.4 to 7.8 cm/s have been used in various studies. ^157-159

Left ventricular systolic dysfunction in this study was taken as septal mitral annular tissue systolic velocity < 6cm/s.

Left ventricular diastolic function was assessed using a combination of the following parameters:

1. Determination of early (E) and late (A) transmitral filling velocities as well as E/A ratio by pulsed wave Doppler interrogation with a 1-2mm sample volume placed at the tips of the mitral valve leaflets in the apical four chamber view.

2. Determination of the deceleration time of the transmitral E velocity (time interval of the transmitral E velocity described above to decay from peak velocity to baseline).

3. Determination of the isovolumic relaxation time (time interval from closure of aortic valve to opening of mitral valve). This was done by pulsed wave Doppler with a 1-2mm sample volume placed in the left ventricular outflow tract between the aortic valve and the mitral valve in the apical five chamber view.

4. Using the pulsed wave tissue Doppler image, early (e’) and late (a’) diastolic mitral annular velocities were obtained from the septal and lateral sides of the mitral annulus in the apical four-chamber view with septal annulus movement aligned with the sample volume line. The ratio of early transmitral inflow to septal diastolic velocity of the mitral annulus (E/e’) was calculated.

E/e’ values have been used for classification of left ventricular filling pressures. ^{100, 101}

 E/e’ ratio less than 8 represents normal LVEDP (left ventricular end-diastolic pressure)

 E/e’ between 8 and 15 represents elevated LVEDP.

 E/e’ ratio greater than 15 represents high LVEDP > 20mmHg.

The septal side was chosen because, in contrast to the lateral side, it moves in a direction more parallel to the ultrasound beam and is less affected by translational movement of the heart; thus there is a narrow band of spectral velocity and angle correlation is not needed. ¹⁶⁰

42

Left ventricular diastolic function was defined as follows:

(a) Normal diastolic function;

(b) Impaired relaxation (grade 1 diastolic dysfunction);

(c) Pseudonormal (grade 2 diastolic dysfunction), and (d) Restrictive (grade 3 to 4 diastolic dysfunction). ^{105, 161}

Normal diastolic function was considered if:

(a) The E/A ratio was between 1 and 2;

(b) Deceleration time (DT) between 160ms and 240ms (c) IVRT between 60ms and 100ms

(d) Tissue Doppler septal e’ velocity > 10cm/s and e’/a’ >1.

(e) E/e’ < 8

Grade 1 diastolic dysfunction (impaired relaxation) was considered if:

(a) The E/A ratio was < 1 (b) Deceleration time > 240ms

(c) Isovolumic relaxation time (IVRT) > 100ms.

(d) Tissue Doppler septal e’ velocity < 10cm/s and e’/a’ < 1.

(e) E/e’< 8.

43

Grade 2 (pseudonormal) diastolic dysfunction was considered if:

In addition to (a) to (c) above for normal diastolic function, there is any combination of:

(a) Tissue Doppler septal e’ velocity < 10cm/s (b) E/e’ >15.

Restrictive diastolic dysfunction was considered if:

(a) Transmitral E/A ratio was > 2 (b) Deceleration time < 160ms (c) IVRT < 60ms

(d) Tissue Doppler septal e’ velocity < 8cm/s.

(e) E/e’ >15.

Protocol 4

Other laboratory tests done include:

Packed cell volume and serum electrolytes was analysed for all subjects by the haematology and chemical pathology laboratory of OAUTHC, Ife.

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DATA ANALYSIS

Data was analyzed using the statistical package for social sciences (SPSS) 17.0 version software (SPSS Inc, Chicago, IL) after it had been entered into a personal computer. Descriptive statistics were computed for continuous variables while frequency tables were generated for categorical variables. The continuous variables were expressed as means + standard deviation while categorical data were expressed as percentages. Differences between the means of two continuous variables were determined with the independent Students t-test and one-way analysis of variance (ANOVA) with Duncan post-hoc test for differences among 3 or more means of continuous data. The differences between proportions were done by the Chi-squared (x²) test.

Logistic regression was used to determine the factors predicting arrhythmias and left ventricular dysfunction among the patients groups. The pearson coefficient test was used to test correlation between relevant variables. Level of statistical significance was defined as p value < 0.05 and a confidence interval of 95%.

45

CHAPTER FOUR RESULTS 4.00: Data

Two hundred subjects completed this study. This comprised 100 subjects with goitre and 100 apparently healthy subjects without goitre. Consecutive recruitment of volunteers was carried out until a total of One hundred (100) patients with goiter and 100 control subjects were gotten to complete the study.

4.01: Sociodemographic characteristics of the Study Population

The sociodemographic characteristics of the study population are as summarized in table 3. The goiter patients were matched for age and sex with their apparently healthy controls counterparts.

The mean age of both groups were similar (46.9 + 13.9 years vs 46.6 + 11.6 years; p = 0.8510).

The age range for the goiter and the control groups were 18-83 years and 18-71 years, respectively. Each group comprised 12 males and 88 females. Forty-seven percent of the goiter group were hyperthyroid, 44% were euthyroid while 9% were hypothyroid. All the apparently healthy subjects in the control group were clinically and biochemically euthyroid.

Eight percent of the goiter population had smoked cigarette as compared to 6% of the control group. This however was not statistically significant. Also, history of significant alcohol consumption was found in 9% and 10% of the goiter and control groups respectively.

The duration of anterior neck swelling ranged from less than one year to 12 years with 89% of the cases having their goiter for less than 5 years.

46

Table 3: Demographic characteristics of the study population.

Parameters Goiter N (%) Control N (%) P value

Age (years) 46.92 + 13.85 46.58 + 11.62 0.8510

Sex; Male Female

12 (12) 88 (88)

12 (12) 88 (88)

1.0000

Diagnosis; Hyperthyroid Euthyroid Hypothyroid

47 (47) 44 (44) 9 (9)

100 (100)

Cigarette Smoking 8 (8) 6 (6) 0.5790

Alcohol Ingestion 9 (9) 10 (10) 0.5160

DONS; 0-5 years 6-10 years

>10 years

89 (89) 9 (9) 2 (2)

0 0 0 Key: DONS=Duration of Neck swelling.

47

4.02: Physical characteristics of the study population.

The physical characteristics of the goiter and the control groups are as summarized in Table 4.

The Body weight, body mass index and body surface area of the study population were significantly higher in the goiter group compared to the control (P=0.041, 0.040 and 0.032 respectively). There was however no significant difference in the height, pulse rate, systolic blood pressure, diastolic blood pressure, pulse pressure and mean arterial blood pressure of both groups (P= 0.851, 0.730, 0.713, 0.692, 0.834 and 0.653 respectively).

48

Table 4: Physical characteristics of the study population.

Parameters Goiter Mean + SD N = 100

Control Mean + SD N = 100

P value

Weight (Kg) 73.00+11.86 70.61+11.21 0.041

Height (m) 1.68+0.04 1.68+0.04 0.851

BMI(Kg/m²) 27.69+1.88 24.94+4.20 0.040

BSA(m²) 1.88+0.10 1.81+0.15 0.032

PR (b/m) 75.86+10.43 74.78+10.88 0.730

SBP (mmHg) 124.50+12.46 123.20+14.63 0.713

DBP (mmHg) 74.44+11.57 72.80+11.98 0.692

PP (mmHg) 49.08+8.52 49.50+11.32 0.834

MABP(mmHg) 91.13+10.60 89.60+11.51 0.653

Key: SD = stardand deviation; BMI= Body mass index; BSA= Body surface area; PR=Pulse rate; SBP= Systolic blood pressure; DBP= Diastolic blood pressure; PP= Pulse Pressure; MABP=Mean arterial Blood Pressure.

49

4.03: Physical characteristics of the study population showing goiter subgroups.

The physical characteristics of the goiter and the control groups are summarized in Table 5.

There was no significant difference in the height of all the groups. However, the hypothyroid group had a significantly higher weight, body mass index and body surface area (P <0.0001 for each) compared to the other groups. There was no statistically significant difference between the pulse rate of the control and the euthyroid groups, however the pulse rate of the hyperthyroid group (105.51+5.75) was significantly higher than the other three groups. The systolic blood pressure of the hyperthyroid group (144.46+10.59) was significantly higher than the other 3 groups (P<0.0001), so also was the pulse pressure (78.94+11.08). There was a significantly higher diastolic blood pressure in the hypothyroid group with a resultant lower pulse pressure (P<0.0001). The mean arterial blood pressure was however not statistically significantly different across the four groups (P=0.0725).

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Table 5: Physical characteristics of the study population showing goiter subgroups.

Parameters Hyperthyroid Mean + SD N = 47

Euthyroid Mean + SD N = 44

Hypothyroid Mean + SD N = 9

Control Mean + SD N = 100

P value

Weight (Kg) 63.58+7.08^a 77.41+8.66 93.00+4.85 70.61+11.21 <0.0001 Height (m) 1.70+0.04 1.67+0.04 1.67+0.05 1.68+0.04 0.0541 BMI(Kg/m²) 22.17+1.62 27.60+3.18 33.30+2.17^f 24.94+4.20 <0.0001 BSA(m²) 1.73+0.11 1.89+0.11 2.01+0.07^f 1.81+0.15 <0.0001 PR (b/m) 105.51+5.75^e 77.96+8.5 59.11+2.03^f 74.78+10.88 <0.0001 SBP (mmHg) 144.46+10.59^e 116.82+11.16 112.22+15.64 123.20+14.63 <0.0001 DBP (mmHg) 66.38+9.42 72.50+7.19 84.44+18.11^f 72.80+11.98 <0.0001 PP (mmHg) 78.94+11.08^e 43.86+9.21 24.44+5.27 49.50+11.32 <0.0001 MABP(mmHg) 92.41+7.89^a 87.27+7.20 93.70+16.70 89.60+11.51 0.0725

KEY: a=p<0.05 for hyperthyroid vs euthyroid and control; b=p<0.05 for hyperthyroid vs hypothyroid; c=p<^{0.05 for} hypothyroid vs euthyroid and control; d=p<0.05 for euthyroid vs control; e=p<0.05 for hyperthyroid vs euthyroid, control and hypothyroid; f=p<0.05 for hypothyroid vs euthyroid, control and hyperthyroid; SD = stardand deviation;

BMI= Body mass index; BSA= Body surface area; PR=Pulse rate; SBP= Systolic blood pressure; DBP= Diastolic blood pressure; PP= Pulse Pressure; MABP=Mean arterial Blood Pressure.

51

4.04: Systemic Blood pressure distribution among the study population.

As shown in table 6, only 2.1% and 22.2% of the hyperthyroid and hypothyroid groups had a normal blood pressure. Blood pressure was however normal in 45.4% and 44% of the euthyroid and control groups respectively. Eighty one point five percent of the hyperthyroid group and 44.5% of the hypothyroid group were hypertensive while 4.6% and 12% of the euthyroid and control groups respectively had blood pressure elevated above 140/90mmHg.

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Table 6: Blood pressure distribution among the study population.

JNC 7 Classification

Hyperthyroid N (%)

Euthyroid N (%)

Hypothyroid N (%)

Control N (%)

Normal 1 (2.1) 20 (45.4) 2 (22.2) 44 (44)

Prehypertension 6 (12.8) 22 (50) 3 (33.3) 44 (44)

Stage 1 34 (72.3) 1 (2.3) 1 (11.2) 8 (8)

Stage 2 6 (12.8) 1 (2.3) 3 (33.3) 4 (4)

Total 47 (100) 44 (100) 9 (100) 100 (100)

Chi² = 88.1010. P<0.0001

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4.04.1: Clinical features of patients with hyperthyroidism.

Among the 47 patients with hyperthyroidism, the commonest clinical feature was excessive sweating which was noted in all of them. Palpitation was noted in 91.5% (43) of all patients.

Weight loss and heat intolerance were noted in 85% (40) while hyperdefaecation was noted in 61.7% (29) of the hyperthyroid patients.

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Figure 1: Clinical features in subjects with Hyperthyroidism

0 5 10 15 20 25 30 35 40 45 50

55

4.04.2: Clinical features of patients with hypothyroidism.

As shown in figure 2, all the patients with hypothyroidism presented with easy fatigability, cold intolerance, weight gain and constipation. Other clinical findings were slow motor activity 33.3% (3), slow mental activity 22.2% (2) and palpitations 11.1% (1).

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Figure 2: Clinical features of patients with Hypothyroidism

57 4.05: Thyroid function of the study population.

All the patients with hyperthyroidism had elevated levels of thyroid hormones and supressed sTSH while all the patients in the hypothyroid group had their levels of thyroid hormones suppressed and their sTSH elevated. However, all the euthyroid patients with goiter and the controls without goiter had normal levels of thyroid hormone and sTSH. The summary is shown in figure 3 below.

58

Figure 3: Summary of the Thyroid function of the study population.

59 CARDIOVASCULAR STUDIES.

4.06: Two-dimensional and M-mode echocardiographic parameters of the study population.

From the two-dimensional and M-mode echocardiographic parameters highlighted in Table 7, 44% (4) of the hypothyroid patients had pericardial effusion while 8.5%, 11.4% and 5% of the hyperthyroid, euthyroid and the control groups respectively showed evidence of pericardial effusion. This showed statistically significant increased pericardial effusion rates in the hypothyroid group (P=0.0120). Also, LAD and LADi, after correction of LAD for body mass index, were significantly higher among the hypothyroid and hyperthyroid groups when compared to the other two groups (0.0005 and <0.0001 respectively).

The hypothyroid group had a significantly higher AOD (3.19+0.45) than the other three groups however when corrected for BSA, the AODi (1.74+0.32) was significantly higher in the

hyperthyroid group (P<0.0001). Also, the means of the IVSD (1.20+0.13cm), LVPWD

(1.18+0.11cm), LVPWS (1.69+0.26cm) and RWT (0.27+0.05) were significantly higher in the hyperthyroid group compared to the other groups (P<0.0001). There was no significant

difference among the groups with respect to RVID. However, when corrected for BSA, the RVIDi was significantly higher in the hyperthyroid group than the other groups (hyperthyroid

=1.00+0.26cm, euthyroid = 0.87+ 0.22cm, hypothyroid =0.90+0.25cm and control = 0.91+0.21cm).

The mean values of the LVIDD, LVIDS and LVIDSi were significantly higher in the

hypothyroid group compared to others (P=0.0059, <0.0001 and <0.0001, respectively) while LVM and LVMi were significantly higher in both hypothyroid and hyperthyroid groups than the other two groups (P<0.0001). There were no significant difference between the

echocardiographic parameters of the euthyroid goiter group and the control group.

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Table 7: Two-dimensional and M-mode echocardiographic parameters of the study population.

Parameters Hyperthyroid Euthyroid Hypothyroid Control P value Peri. Eff n(%) 4 (8.5) 5 (11.4) 4 (44.4)^f 5 (5) <0.0001 LAD (cm) 3.66+0.47^a 3.36+0.60 3.93+0.50^c 3.37+0.53 0.0005 LADi (cm/M²) 2.13+0.32^a 1.78+0.35 1.90+0.25^c 1.87+0.33 <0.0001 AOD (cm) 2.99+0.44 2.72+0.37 3.19+0.45^f 2.77+0.35 0.0001 AODi (cm/M²) 1.74+0.32^e 1.44+0.21 1.54+0.23 1.44+0.22 <0.0001 IVSD (cm) 1.20+0.13^e 0.93+0.13 1.03+0.13 0.99+0.10 <0.0001 LVPWD (cm) 1.18+0.11^e 0.93+0.13 1.00+0.09 0.97+0.10 <0.0001 LVPWS (cm) 1.69+0.26^e 1.34+0.28 1.28+0.13 1.47+0.25 <0.0001 RVID (cm) 1.72+0.39 1.64+0.38 1.87+0.49 1.64+0.34 0.2282 RVIDi

(cm/M²)

1.00+0.26^e 0.87+0.22 0.90+0.25 0.91+0.21 0.0369

LVIDD (cm) 4.40+0.65 4.45+0.59 5.13+0.78^f 4.39+0.56 0.0059 LVIDDi

(cm/M²)

2.56+0.40 2.36+0.36 2.47+0.39 2.44+0.38 0.1080

LVIDS (cm) 2.66+0.64 2.80+0.50 4.09+0.74^f 2.77+0.53 <0.0001 LVIDSi

(cm/M²)

1.55+0.39 1.49+0.29 1.97+0.38^f 1.54+0.32 <0.0001

LVM (g) 174.51+33.66^a 122.23+28.79 172.00+44.73^c 129.06+23.57 <0.0001 LVMi (g/M²) 101.25+19.97^a 64.89+16.29 82.98+22.41^c 71.68+14.38 <0.0001

RWT 0.27+0.05^e 0.21+0.04 0.20+0.04 0.22+0.04 <0.0001

KEY: a=p<0.05 for hyperthyroid vs euthyroid and control; b=p<0.05 for hyperthyroid vs hypothyroid; c=p<0.05 for hypothyroid vs euthyroid and control; d=p<0.05 for euthyroid vs control; e=p<0.05 for hyperthyroid vs euthyroid, control and hypothyroid; f=p<0.05 for hypothyroid vs euthyroid, control and hyperthyroid; Peri. Eff=pericardial effusion; LAD=left atrial diameter; LADi = left atrial diameter index; AOD=Aortic root diameter; AODi=aortic root diameter index; IVSD=interventricular septal thickness in diastole; LVPWD=left ventricular posterior wall thickness in diastole; LVPWS=left ventricular posterior wall thickness in systole; RVID=right ventricular internal dimension ; RVIDi=right ventricular internal dimension index; LVIDD=left ventricular internal dimension in diastole;LVIDDi=left ventricular internal dimension in diastole index; LVIDS=left ventricular internal dimension in systole; LVIDSi=left ventricular internal dimension in systole index; LVM=left ventricular mass; LVMi=left ventricular mass index; RWT=relative wall thickness

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4.07: Left ventricular systolic function parameters of the study population.

Table 8 below showed that hypothyroid patients had significantly higher stroke volume than all the other groups (P=0.0016). Though the stroke index was not significantly different across the groups (P= 0.0777), the hypothyroid group had a significantly higher stroke index compared to the euthyroid and the control group (P=0.026 and 0.017 respectively). The cardiac output (9.62+4.69 L/min), cardiac index (5.57+2.70 L/M²), left ventricular ejection fraction

(72.47+9.64%) and fractional fibre shortening (41.58+8.78%) were significantly higher in the hyperthyroid group than the other three groups (P=0.0005, <0.0001, <0.0001 and <0.0001 respectively).

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Table 8: Left ventricular systolic function parameters of the study population.

Parameters Hyperthyroid Euthyroid Hypothyroid Control P value SV (ml) 91.03+43.97 89.77+35.29 108.25+46.96^f 88.90+37.14 0.0016 SI (ml/M²) 52.77+25.40 49.28+19.32 56.86+23.36^f 49.43+21.45 0.0777 CO (L/min) 9.62+4.69^e 7.15+2.79 8.49+3.39 6.97+3.39 0.0005 CI(L/min/M²) 5.57+2.70^e 3.80+1.54 4.09+1.66 3.87+1.92 <0.0001 LVEF (%) 72.47+9.64^e 65.21+8.09 48.44+7.73 65.35+8.70 <0.0001 LVFS (%) 41.58+8.78^e 35.89+6.02 24.67+4.53 36.05+6.36 <0.0001 KEY: a=p<0.05 for hyperthyroid vs euthyroid and control; b=p<0.05 for hyperthyroid vs hypothyroid; c=p<^0.05 for hypothyroid vs euthyroid and control; d=p<0.05 for euthyroid vs control; e=p<0.05 for hyperthyroid vs euthyroid, control and hypothyroid; f=p<0.05 for hypothyroid vs euthyroid, control and hyperthyroid; SV=stroke volume; SI=stroke index; CO=cardiac output; CI=cardiac index; LVEF=left ventricular ejection fraction; LVFS=left ventricular fractional shortening.

63

4.08: Summary of the left ventricular systolic function.

Table 9 summarized the pattern of systolic function across the groups. All the 9 (100%) patients in the hypothyroid group had depressed left ventricular systolic function (LVEF< 50% and LVFS <25%). Only 3 (6.4%) of the hyperthyroid group had depressed left ventricular systolic function while 4.5% and 3% of the euthyroid and control groups respectively had depressed left ventricular systolic function. Enhanced systolic function was seen in 38.3%, 9.1% and 7% of the hyperthyroid, euthyroid and control group respectively. In all, 14% of the goiter patients had left ventricular systolic dysfunction compared to 3% of the control group (P<0.0001).

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Table 9: Summary of the left ventricular systolic function of the study population.

Hyperthyroid N (%)

Euthyroid N (%)

Hypothyroid N (%)

Control N (%)

Enhanced 18 (38.3) 4 (9.1) 0 7 (7)

Normal 26 (55.3) 38 (86.4) 0 90 (90)

Depressed 3 (6.4) 2 (4.5) 9 (100) 3 (3) Total 47 (100) 44 (100) 9 (100) 100 (100) Chi² =88.1010 P<0.0001

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4.09: Doppler echocardiographic findings of the study population.

Table 10 summarized the Doppler echocardiographic findings of the study population. It showed that there were no significant differences among the groups for the MV E velocity and the MV E/A ratio (P=0.0859 and 0.1468). However, the MV A velocity was significantly higher in the hyperthyroid group. The deceleration and isovolumic relaxation times were significantly prolonged in both the hyperthyroid (219.02+36.56 and 87.36+15.62 ms) and hypothyroid (206.67+64.93 and 90.11+32.03 ms) groups compared to the other two groups. The TV E and TV A velocities were not significantly different across the groups however the TV E/A ratio were significantly lower in the hypothyroid and hyperthyroid groups. The e’, s’ and e’/ a’ ratio (8.33+4.24, 7.56+2.60 and 0.83+0.08 respectively) were significantly lower in the hypothyroid group (P<0.0001) compared to the other 3 groups while the a’ and s’ were higher in the

hyperthyroid group (P=0.0268 and <0.0001) compared to the other groups. Also, the MV E vel/e’ (13.34+12.01) was significantly higher in the hypothyroid group.

There was a significantly higher prevalence of regurgitation across all the cardiac valves in the hypothyroid group (MR and TR =77.8% ; P=0.0032, AR = 22.2%; P=0.044 and PR = 44.4%;

P=0.0051).

Finally, there were no significant differences in the Doppler echocardiographic parameters between the euthyroid and the control groups.

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Table 10: Doppler echocardiographic findings of the study population.

Parameters Hyperthyroid Euthyroid Hypothyroid Control P value MV E vel (m/s) 0.78+0.20 0.76+0.15 0.70+0.20 0.71+0.15 0.0859 MV A vel (m/s) 0.65+0.15^e 0.58+0.12 0.61+0.25 0.59+0.10 0.0126

MV E/A 1.23+0.33 1.36+0.32 1.33+0.70 1.34+0.35 0.1468

Dec Time (ms) 219.02+36.56^a 199.16+26.97 206.67+64.93^c 200.10+29.06 0.0081 IVRT (ms) 87.36+15.62^a 79.73+12.94 90.11+32.03^c 80.15+14.12 0.0535 TV E vel (ms) 0.49+0.12 0.54+0.21 0.44+0.11 0.54+0.29 0.4228 TV A vel (ms) 0.42+0.13 0.40+0.13 0.51+0.10 0.42+0.15 0.1624 TV E/A 1.21+0.31^a 1.37+0.32 0.87+0.32^c 1.36+0.29 0.0001 e’ (cm/S) 11.89+2.12 11.07+2.04 8.33+4.24^f 11.59+1.70 <0.0001 a’ (cm/S) 10.79+2.08^e 9.68+1.78 9.78+4.66 9.72+1.91 0.0268 s’ (cm/S) 11.40+1.85 10.52+1.55 7.56+2.60^f 10.12+1.66 <0.0001 MV E vel /e’ 6.81+2.43 7.55+4.70 13.34+12.01^f 7.27+1.53 <0.0001 e’/ a’ 1.12+ 0.17 1.14+0.12 0.83+0.08^f 1.22+0.17 <0.0001

MR n(%) 13(27.7) 3 (6.82) 7(77.8)^f 6 (6) <0.0001

TR n(%) 5(10.6) 2 (4.5) 7(77.8)^f 4 (4) <0.0001

AR n(%) 7(14.9) 0 (0) 2 (22.2)^f 0(0) 0.0090

PR n(%) 10(21.3) 1 (2.3) 4 (44.4)^f 3(3) 0.0040

KEY: a=p<0.05 for hyperthyroid vs euthyroid and control; b=p<0.05 for hyperthyroid vs hypothyroid; c=p<0.05 for hypothyroid vs euthyroid and control; d=p<0.05 for euthyroid vs control; e=p<0.05 for hyperthyroid vs euthyroid, control and hypothyroid; f=p<0.05 for hypothyroid vs euthyroid, control and hyperthyroid; MV E vel= early transmitral inflow velocity; MV A vel= late transmitral inflow velocity; MV E/A= ratio of early to late transmitral inflow velocity; Dec Time= early transmitral flow velocity deceleration time; IVRT= Isovolumic relaxation time.TV Evel= early transtricuspid inflow velocity; TV Avel= late transtricuspid inflow velocity; TV E/A=ratio of early to late transtricuspid inflow velocity: e’ = tissue Doppler early mitral annular relaxation velocity; a’ = tissue Doppler late mitral annular relaxation velocity; s’ = tissue Doppler mitral annular systolic velocity; MV E vel/e’ = ratio of early transmitral inflow velocity to early annular relaxation velocity; MR=Mitral regurgitation; TR= Tricuspid regurgitation; AR= Aortic regurgitation; PR= Pulmonary regurgitation.

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4.10: Left ventricular diastolic function of the study population.

As seen in table 11 below, all the hypothyroid patients had diastolic dysfunction. 23.4% (11) of the hyperthyroid patients, 9.2% (4) of euthyroid group and 11% (11) of the control group had diastolic dysfunction. In total, 24% of all patients with goiter had diastolic dysfunction as compared to 11% of the control group.

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Table 11: Summary of the Doppler echocardiography assessment of the left ventricular

In document Valores y estilo de vida de los niños y niñas de 9 y 10 años de edad, estudio realizado en la escuela “Dos de Agosto” de la ciudad de Alamor, provincia de Loja en el año lectivo 2012 - 2013 (página 96-123)