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Effects of Acute Thiamine Deficiency on the Electrocardiogram of the Chick*
Effects of Acute Thiamine Deficiency on the Electrocardiogram of the Chick* PAUL D. STURKIE Laboratory of Avian Physiology, Rutgers University, New Brunswick, New Jersey (Received for publication August 24, 1953)
ARDIAC abnormalities resulting from thiamine deficiency have been reported in man and experimental animals by a number of workers. Some of these have been reviewed and discussed by Hundley et al. (1945). Electrocardiographic changes in swine resulting from the deficiency include: bradycardia, prolonged P-R interval, second degree A-V block, complete A-V block, A-V dissociation, and others (Wintrobe et al., 1943). Partridge (1948) has also reported disturbances in A-V conduction in swine as a result of thiamine deficiency. In rats, sinus arrhythmia, sinus arrest, atrial fibrilation, A-V nodal rhythm, first degree A-V block, shifting pacemaker, and other abnormalities have been reported by Hundley et al. (1945). Some of these abnormalities were also observed in thiamine-deficient cats (Toman et al., 1945). A number of workers have reported the effects of deficiencies in thiamine and other B complex vitamins upon growth and behavior of the chicken, but none has studied the effects of these deficiencies upon the electrocardiogram. Carter and Drury (1929) ran ECG's on a few pigeons fed a diet deficient in the B complex vitamins (polished rice). They did not show records, but they reported that most of the birds exhibited second-degree A-V block, sinus arrhythmia, and bradycardia. * Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University, the State University of New Jersey, New Brunswick, Department of Poultry Husbandry.
According to these workers, sectioning of the vagi or administration of atropine abolished the block and produced normal sinus rhythm. Swank and Bessey (1942) reported bradycardia, first degree A-V block, and inverted T waves in acutethiamine deficient pigeons, but tachycardia was common in the chronically deficient birds. The object of this experiment was to study the effects of acute thiamine deficiency in young chicks upon the electrocardiogram. PROCEDURE
Three groups of White Leghorn male chicks, 2 and 12 days of age, were fed a diet completely deficient in thiamine. The diet consisted of casein, 25 parts; gelatin, 8.5; cornstarch, 30; dextrose, 25; cellulose, 4; minerals, 6; and vitamins 0.5 parts. The diet contained no fat, but satisfactory growth was obtained in the control groups. Adequate amounts of minerals were supplied as used and recommended by Briggs (1946). The vitamin mixture included niacin, riboflavin, pantothenic acid, choline, pyridoxine, inositol, p-aminobenzoic acid, folic acid, alpha tocopherol, 2-methyl naptho quinone, and A and D in amounts recommended by the Committee on Animal Nutrition (1950). ECG's were taken one week after the birds were placed on the deficient diet, and at varying intervals until the birds died or the experiment was terminated. Standard limb leads were used as described by Sturkie (1949).
508
Downloaded from http://ps.oxfordjournals.org/ at Florida International University on June 10, 2015
C
ELECTROCARDIOGRAM OF T H I A M I N E D E F I C I E N T CHICKS
TABLE 1.—Effects of acute thiamine deficiency on mortality of While Leghorn chicks Experiment Total Age of chicks when started (days) No. chicks started No. dead within 15 days Percent dead within 15 days
1
2
3
2
2 32 23 72
12 10 6 60
n 12 57
63 41 65
The mortality of the chicks and the types and distribution of heart abnormalalities observed are shown in Tables 1 and 2. Fifteen days after the birds were on the deficient diet, one half or more of them were dead. The unusually high mortality in Experiment 2 was due in p a r t to extreme changes in environmental temperature, to which thiamine-deficient animals are extremely susceptible. Most of the deficient birds died within 21 to 28 days. Description of Abnormal ECG's. The E C G ' s of the majority of the abnormal birds were characterized by depression of S-T (Figure 2), and b y abnormalities concerning the initiation, rhythm, and rate of discharge of the S-A node. T h e latter include bradycardia and sinus arrhythmia (the most frequent), and mild and severe sinus arrest. Some of the E C G ' s revealed more than one of these conditions. Sinus arrhythmia was usually the first abnormality observed in the early stages
A—«
vf
of thiamine depletion. Sinus arrest, and bradycardia appeared in later and terminal stages of depletion. The heart rate of the normal chick ranges from about 250 to more than 300, whereas the rates for most of the deficient chicks just before death ranged from 90 to 190 per minute. (See Figures 1 and 2). It is likely t h a t the inanition, characteristic of the terminal stages of thiamine depletion, resulted in the bradycardia as was reported in starved pigeons by Swank and Bessey (1942), and by others for other species. When they force-fed their thiamine deficient birds, bradycardia was rarely observed. Thiamine was administered to a few chicks in the early stages of the depletion and the abnormal E C G ' s reverted to normal. Approximately 26 percent of the E C G ' s were characterized by irregular and infrequent pauses in which the P-P interval is usually about I5 times the normal interval (mild sinus arrest). This condition and sinus arrhythmia also occur in potassiumdeficient chicks and have been previously described (Sturkie, 1950). Nearly twentythree percent of the E C G ' s exhibited infrequent b u t prolonged pauses (severe sinus arrest). The duration of the pauses ranged from 2\ to about 3 | times the normal P-P or S-S interval, b u t the pause was never a multiple of the normal interval, and the P-S interval before and after the pause was constant (Figure 1).
Vf
ir"'.
Electrocardiograms of thiamine deficient chicks. FIG. 1. Shows bradycardia, (heart rate 173) sinus arrest, and low amplitude of all the waves. Note the long pause (X) and the absence of P and 5 waves. Black dots indicate P waves. FIG. 2. Shows bradycardia (heart rate 161) and depression of the S-T segment. Records standardized at 1 mv equals 2 cms. Chart speed equals 25 mm. per second.
Downloaded from http://ps.oxfordjournals.org/ at Florida International University on June 10, 2015
RESULTS
509
510
P. D. STURKIE
TABLE 2.—Distribution and description of abnormal electrocardiograms of thiamine deficient chicks Experiment 1
3
17
13
10
40
11
10
10
31
62.0
4 4 8 4 2 3
5 7 4 2 4 1
8 8 5 2 1 0
17 19 17 8 7 4
54.8* 61.3 54.8 25.8 22.5 12.9
0
1
1
1
3.2
Total
Percent
* Calculated on number abnormal (31). Most ECG's exhibited more than one abnormality, hence the discrepancies in numbers.
The pauses resulting from sinus arrest were often accompanied, or punctuated, by one or more ectopic beats. In one case where the sinus rate was inordinately slow (90 per minute) but regular, a nodal rhythm developed with a higher rate than that of the sinus. This led to A-V dissociation, a condition which has also been reported for the potassium-deficient chick (Sturkie, 1952). The amplitude of many of the ECG's was low. DISCUSSION
No cases of A-V block were observed in the chicks of this study. This abnormality is likewise rare among adult chickens fed a diet low in thiamine (Sturkie, unpublished). These results are contrary to those of Carter and Drury (1929) and Swank and Bessey (1942) who reported a high incidence of A-V block in thiaminedepleted pigeons. A-V block is one of the principal abnormalities of potassuim-deficient chicks (Sturkie, 1950, 1952). The diet used by Carter and Drury was deficient not only in thiamine but in other B vitamins as well. However, the author (unpublished) has shown that acute niacin deficiency or riboflavin deficiency in the chick does not produce abnormal ECG's. Moreover, the effects of acute niacin and thiamine deficiencies on the ECG's
SUMMARY
White Leghorn male chicks 2 and 12 days old fed a diet completely deficient in thiamine begin to develop heart abnormalities within 7 to 10 days. Within 15 days approximately half of the chicks were dead, and within 21 to 28 days nearly all were dead. The abnormalities observed in the ECG's in decreasing frequency of occurrence were: bradycardia, depression of S-T segment, sinus arrhythmia, sinus arrest, ectopic beats, and A-V dissociation with nodal rhythm. REFERENCES Briggs, G. M., 1946. Nicotinic acid deficiency in turkey poults and the occurrence of perosis. J. Nutrition, 31: 79-84. Carter, C. W., and A. N. Drury, 1929. Heart block in rice-fed pigeons. J. Physiol. 68: Proc. 1-2. Committee on Animal Nutrition, National Research Council, 1950. Report on recommended nutrient allowances for poultry. Hundley, J. M., L. L. Ashburn and W. H. Sebrell, 1945. The electrocardiogram in chronic thiamine deficiency in rats. Am. J. Physiol. 144: 404-414. Partridge, J. F., 1948. Cardiac lesions in thiamine deficiency. British Heart Journal, 10: 252-262. Sturkie, P. D., 1949. The electrocardiogram of the chicken. Am. J. Vet. Res. 10: 168-175. Sturkie, P. D., 1950. Abnormal electrocardiograms of chickens produced by potassium deficiency and effects of certain drugs on the abnormalities. Am. J. Physiol. 162: 538-544. Sturkie, P. D., 1952. Further studies of potassium deficiency on the electrocardiograms of chickens. Poultry Sci. 31:648-650. Sturkie P. D., 1952 and 1953. Unpublished. Swank, R. L., and O. A. Bessey, 1942. Production and study of cardiac failure in thiamine deficient pigeons. Arch. Int. Med. 70: 763-776. Toman, J. E., G. M. Everett, R. H. Oster and D. C. Smith, 1945. Origin of cardiac disorders in thiamine-deficient cats. Proc. Soc. Exp. Biol. Med. 58: 65-67. Wintrobe, M. M., P. Alcayaga, S. Humphreys and and R. H. Follis, Jr., 1943. Electrocardiographic changes associated with thiamine deficiency in pigs. Bull. Johns Hopkins Hospital 73: 169-195.
Downloaded from http://ps.oxfordjournals.org/ at Florida International University on June 10, 2015
Chicks on which E C G ' s were taken Chicks with abnormal ECG's Description of ECG's S-T depression Bradycardia Sinus arrhythmia Sinus arrest (mild) Sinus arrest (severe) Ectopic beats A-V dissociation and nodal rhythm
2 Number
of chicks are not essentially different from those of thiamine alone, but the chick mortality is higher on both deficiencies.
ARDIAC abnormalities resulting from thiamine deficiency have been reported in man and experimental animals by a number of workers. Some of these have been reviewed and discussed by Hundley et al. (1945). Electrocardiographic changes in swine resulting from the deficiency include: bradycardia, prolonged P-R interval, second degree A-V block, complete A-V block, A-V dissociation, and others (Wintrobe et al., 1943). Partridge (1948) has also reported disturbances in A-V conduction in swine as a result of thiamine deficiency. In rats, sinus arrhythmia, sinus arrest, atrial fibrilation, A-V nodal rhythm, first degree A-V block, shifting pacemaker, and other abnormalities have been reported by Hundley et al. (1945). Some of these abnormalities were also observed in thiamine-deficient cats (Toman et al., 1945). A number of workers have reported the effects of deficiencies in thiamine and other B complex vitamins upon growth and behavior of the chicken, but none has studied the effects of these deficiencies upon the electrocardiogram. Carter and Drury (1929) ran ECG's on a few pigeons fed a diet deficient in the B complex vitamins (polished rice). They did not show records, but they reported that most of the birds exhibited second-degree A-V block, sinus arrhythmia, and bradycardia. * Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University, the State University of New Jersey, New Brunswick, Department of Poultry Husbandry.
According to these workers, sectioning of the vagi or administration of atropine abolished the block and produced normal sinus rhythm. Swank and Bessey (1942) reported bradycardia, first degree A-V block, and inverted T waves in acutethiamine deficient pigeons, but tachycardia was common in the chronically deficient birds. The object of this experiment was to study the effects of acute thiamine deficiency in young chicks upon the electrocardiogram. PROCEDURE
Three groups of White Leghorn male chicks, 2 and 12 days of age, were fed a diet completely deficient in thiamine. The diet consisted of casein, 25 parts; gelatin, 8.5; cornstarch, 30; dextrose, 25; cellulose, 4; minerals, 6; and vitamins 0.5 parts. The diet contained no fat, but satisfactory growth was obtained in the control groups. Adequate amounts of minerals were supplied as used and recommended by Briggs (1946). The vitamin mixture included niacin, riboflavin, pantothenic acid, choline, pyridoxine, inositol, p-aminobenzoic acid, folic acid, alpha tocopherol, 2-methyl naptho quinone, and A and D in amounts recommended by the Committee on Animal Nutrition (1950). ECG's were taken one week after the birds were placed on the deficient diet, and at varying intervals until the birds died or the experiment was terminated. Standard limb leads were used as described by Sturkie (1949).
508
Downloaded from http://ps.oxfordjournals.org/ at Florida International University on June 10, 2015
C
ELECTROCARDIOGRAM OF T H I A M I N E D E F I C I E N T CHICKS
TABLE 1.—Effects of acute thiamine deficiency on mortality of While Leghorn chicks Experiment Total Age of chicks when started (days) No. chicks started No. dead within 15 days Percent dead within 15 days
1
2
3
2
2 32 23 72
12 10 6 60
n 12 57
63 41 65
The mortality of the chicks and the types and distribution of heart abnormalalities observed are shown in Tables 1 and 2. Fifteen days after the birds were on the deficient diet, one half or more of them were dead. The unusually high mortality in Experiment 2 was due in p a r t to extreme changes in environmental temperature, to which thiamine-deficient animals are extremely susceptible. Most of the deficient birds died within 21 to 28 days. Description of Abnormal ECG's. The E C G ' s of the majority of the abnormal birds were characterized by depression of S-T (Figure 2), and b y abnormalities concerning the initiation, rhythm, and rate of discharge of the S-A node. T h e latter include bradycardia and sinus arrhythmia (the most frequent), and mild and severe sinus arrest. Some of the E C G ' s revealed more than one of these conditions. Sinus arrhythmia was usually the first abnormality observed in the early stages
A—«
vf
of thiamine depletion. Sinus arrest, and bradycardia appeared in later and terminal stages of depletion. The heart rate of the normal chick ranges from about 250 to more than 300, whereas the rates for most of the deficient chicks just before death ranged from 90 to 190 per minute. (See Figures 1 and 2). It is likely t h a t the inanition, characteristic of the terminal stages of thiamine depletion, resulted in the bradycardia as was reported in starved pigeons by Swank and Bessey (1942), and by others for other species. When they force-fed their thiamine deficient birds, bradycardia was rarely observed. Thiamine was administered to a few chicks in the early stages of the depletion and the abnormal E C G ' s reverted to normal. Approximately 26 percent of the E C G ' s were characterized by irregular and infrequent pauses in which the P-P interval is usually about I5 times the normal interval (mild sinus arrest). This condition and sinus arrhythmia also occur in potassiumdeficient chicks and have been previously described (Sturkie, 1950). Nearly twentythree percent of the E C G ' s exhibited infrequent b u t prolonged pauses (severe sinus arrest). The duration of the pauses ranged from 2\ to about 3 | times the normal P-P or S-S interval, b u t the pause was never a multiple of the normal interval, and the P-S interval before and after the pause was constant (Figure 1).
Vf
ir"'.
Electrocardiograms of thiamine deficient chicks. FIG. 1. Shows bradycardia, (heart rate 173) sinus arrest, and low amplitude of all the waves. Note the long pause (X) and the absence of P and 5 waves. Black dots indicate P waves. FIG. 2. Shows bradycardia (heart rate 161) and depression of the S-T segment. Records standardized at 1 mv equals 2 cms. Chart speed equals 25 mm. per second.
Downloaded from http://ps.oxfordjournals.org/ at Florida International University on June 10, 2015
RESULTS
509
510
P. D. STURKIE
TABLE 2.—Distribution and description of abnormal electrocardiograms of thiamine deficient chicks Experiment 1
3
17
13
10
40
11
10
10
31
62.0
4 4 8 4 2 3
5 7 4 2 4 1
8 8 5 2 1 0
17 19 17 8 7 4
54.8* 61.3 54.8 25.8 22.5 12.9
0
1
1
1
3.2
Total
Percent
* Calculated on number abnormal (31). Most ECG's exhibited more than one abnormality, hence the discrepancies in numbers.
The pauses resulting from sinus arrest were often accompanied, or punctuated, by one or more ectopic beats. In one case where the sinus rate was inordinately slow (90 per minute) but regular, a nodal rhythm developed with a higher rate than that of the sinus. This led to A-V dissociation, a condition which has also been reported for the potassium-deficient chick (Sturkie, 1952). The amplitude of many of the ECG's was low. DISCUSSION
No cases of A-V block were observed in the chicks of this study. This abnormality is likewise rare among adult chickens fed a diet low in thiamine (Sturkie, unpublished). These results are contrary to those of Carter and Drury (1929) and Swank and Bessey (1942) who reported a high incidence of A-V block in thiaminedepleted pigeons. A-V block is one of the principal abnormalities of potassuim-deficient chicks (Sturkie, 1950, 1952). The diet used by Carter and Drury was deficient not only in thiamine but in other B vitamins as well. However, the author (unpublished) has shown that acute niacin deficiency or riboflavin deficiency in the chick does not produce abnormal ECG's. Moreover, the effects of acute niacin and thiamine deficiencies on the ECG's
SUMMARY
White Leghorn male chicks 2 and 12 days old fed a diet completely deficient in thiamine begin to develop heart abnormalities within 7 to 10 days. Within 15 days approximately half of the chicks were dead, and within 21 to 28 days nearly all were dead. The abnormalities observed in the ECG's in decreasing frequency of occurrence were: bradycardia, depression of S-T segment, sinus arrhythmia, sinus arrest, ectopic beats, and A-V dissociation with nodal rhythm. REFERENCES Briggs, G. M., 1946. Nicotinic acid deficiency in turkey poults and the occurrence of perosis. J. Nutrition, 31: 79-84. Carter, C. W., and A. N. Drury, 1929. Heart block in rice-fed pigeons. J. Physiol. 68: Proc. 1-2. Committee on Animal Nutrition, National Research Council, 1950. Report on recommended nutrient allowances for poultry. Hundley, J. M., L. L. Ashburn and W. H. Sebrell, 1945. The electrocardiogram in chronic thiamine deficiency in rats. Am. J. Physiol. 144: 404-414. Partridge, J. F., 1948. Cardiac lesions in thiamine deficiency. British Heart Journal, 10: 252-262. Sturkie, P. D., 1949. The electrocardiogram of the chicken. Am. J. Vet. Res. 10: 168-175. Sturkie, P. D., 1950. Abnormal electrocardiograms of chickens produced by potassium deficiency and effects of certain drugs on the abnormalities. Am. J. Physiol. 162: 538-544. Sturkie, P. D., 1952. Further studies of potassium deficiency on the electrocardiograms of chickens. Poultry Sci. 31:648-650. Sturkie P. D., 1952 and 1953. Unpublished. Swank, R. L., and O. A. Bessey, 1942. Production and study of cardiac failure in thiamine deficient pigeons. Arch. Int. Med. 70: 763-776. Toman, J. E., G. M. Everett, R. H. Oster and D. C. Smith, 1945. Origin of cardiac disorders in thiamine-deficient cats. Proc. Soc. Exp. Biol. Med. 58: 65-67. Wintrobe, M. M., P. Alcayaga, S. Humphreys and and R. H. Follis, Jr., 1943. Electrocardiographic changes associated with thiamine deficiency in pigs. Bull. Johns Hopkins Hospital 73: 169-195.
Downloaded from http://ps.oxfordjournals.org/ at Florida International University on June 10, 2015
Chicks on which E C G ' s were taken Chicks with abnormal ECG's Description of ECG's S-T depression Bradycardia Sinus arrhythmia Sinus arrest (mild) Sinus arrest (severe) Ectopic beats A-V dissociation and nodal rhythm
2 Number
of chicks are not essentially different from those of thiamine alone, but the chick mortality is higher on both deficiencies.