Ballistocardiograms on trained (unanesthetized) dogs
1
Abstracts 847 stretched out and the head held upright. From time to time slight head movements produce minor artefacts. The chicken will generally remain in this position for prolonged periods. The tracing has to be run at high paper speeds (50 or 100 mm./sec.) if details are to be distinguished. The usual parts of the ULF ballisto- cardiogram can be seen in the tracing although they are not c>asily discerned. Keasonable reproducibility is found. The tracing may also be run slowly and pharma- cologically active preparations introduced through a plastic cannula into the large alar (wing) vein without constraining thr ITI,F hallistocardiograph bed. “I7‘R \*.ow FREQ”ENC\ RALLISTOCARDIOGRAM DURING BREATHING. H. Kfmsrh, Institute of Physiology, Uni- versity of Bonn, Bonn. Germany. Ry means of a compensation circuit it is possible to eliminate morr or less completely the respiratory oscil- lations from ULF ballistocardiograms. The output of a ruljber tube respiration recorder with an electronic transducer is mixed with the ballistocardiograph ampli- fi~r output (changed poles) and fed to a third amplifier. It is possible to balance the amplitude of the ballisto- cardiograph and respiration amplifier and to change thr phase in a certain range. After optimal balancing of the amplitudes. phase and time constant, the resultant curve bears little respiratory variation. \Vith this rquipment one may perform “true” simul- taneous investigations of cardiac output both by ballisto- cardiograms and other methods (direct Fick, Stewart- Hamilton) without regard to possible differences b+ tucen cardiac output in free breathing and when hold- inq thr breath. \Yr are able to get the “physiologic” cardiac output during breathing, which is not in all casts the. samr as in holding the breath. We find the cardiac olltput in basal respiration about 10 per cent higher than while holding the breath. This may be one of the rea- sons .,vhy simultaneous investigations of cardiac output by direct Fick and ballistocardiographic methods differ hy about 10 prr cvnt. BALLISTOC.ARDIOGRAMS ON TRAINED (UNANESTHETIZED) DOGS. IVillinm Schwarlz. Dept. of Therapeutic Research. l:nivrrsity of Pennsylvania, Philadelphia, Pa. ‘l‘hat the ultralow frequency ballistocardiographic technic gives fine records on anesthetized dogs has been demonstrated in several laboratories. However, the control rrcords on these animals have often been of a form which. judging from experience with human rec- ords, should be judged as abnormal even though the ballistocardiogram could often be made normal by car- diac stimulation or abdominal compression. ‘This study was designed to answer the question: Is this abnormality of form due to the anesthetic or to some inherrnt difference in cardiac physiology brt\vren man and dog? A small ULF ballistocardiogram, designed fol- animal experiments, was used and acceleration was recorded. Two large dogs were trained for several wc*caks until they would lie still on the instrument. \Yhen good training had been attained, simultaneous ballisto- cardiograms and electrocardiograms were secured. These- records were normal in every respect. One of th<, dogs was then anesthetized by morphine, dialurr- thanc and nembutal. While anesthetized, he gave a record very abnormal by human standards. There:- forr, it seems likely that the abnormality of ballistic OCTOBER 1960 form so often found in anesthetized dogs is not due to anatomic or physiologic differences betwrcm doq and man but to a true abnormality of cardiac function due either to an advrrse effect of the anesthetic or to the opcr- ative procedure which so often accompanies such cxprri- mrnts. CARDIAC CONTROI. IN EXERCISE. Ems/ JoXl. .il.l).. Iini- versity of Kentucky, Lexington? Ky. The current physiologic concept of cardiac control in exercise is based upon newer evidence obtained in experimental studies with normal human subjects. In contrast to observations with the isolated heart or with the heart-lung preparation, size and strokr volume of the human heart adapt themselves during crcrcise in accordance with patterns of the-ir own. Diastolic end volumes become smaller and vrntricular output rises. Thus the seemingly anachronous situation devrlops of a heart reduced in size expellin, cr larg-er stroke voltrmcz. The explanation of this apparent paradox is that resid- ual blood becomes circulating blood. and at the. height of systolk during exercise the cardiac chambers arc almost empty. At rrst as well as during exercise, tlrca heart of th( athlete is characterized by morphologic and functional features of which the following are relrvant for purposes of this presentation: At rest the athlrtc has a large] heart and uses smaller stroke volumes. During rxercisc his heart becomes smaller than that of the untrained and steps up ventricular output to maximum. In accord- ance with these facts the following ballistocardiographic findings were expected: athletes’ tracings to show Iowrr amplitudes of I-J and K at rest and hishrr amplitudes during exercise. Data collected in this laboratory during wrll controlled exercise exprriments with trained and untrained sub- jects, all of whom ran a distance of 2 miles. failed to comply with the above hypothrtic postulates. The evidence was presented and alternativr intrrpretations given. The suggestion was made that esistiny theories of cardiac control in exercise rrquire major changes. BALLISTOCARDIOGRAM IN ACROMEGALY. Jcr:_y I~wXolec. M.D., Medical Academy, Poznan. Poland. A direct ballistocardiographic method with the use of a resonance hallistocardiograph recording displacement curves was applied. Ballistocardiograms were prr- formed in sixteen patients with acromegaly in the aqr group thirty-six to fifty-seven. In most of these casrs an enlargement of heart volume (Jonsell method) and the prolongation of Q-T interval (rlrctrocardiograrn 1 were found. The time of the ballistocardiographic waves and th<.il relation to ‘2 and R waves of the simultaneously I‘<*- corded electrocardiographic curve were calculatrd and compared to values obtained in normal subjects. In all acromegalic patients a distinct prolongation of Q-C;, Q-H, Q-I, Q-J and R-H intervals was observed. ?‘hC time of H-I, I-J, J-K, K-L waves did not differ from nor- mal values. In all cases of acromegaly thr coefficient H-K/R-H was diminished (acromcsalv: 1 .‘) 0.29 : normal : 3.3-0.02). The amplitude of systolic compleves and diastolic waves did not differ significantly in comparison to tllc normal. Variations in the trace during normal br<*ath- ing were found only in six casts (gradI- 2 acccjrdinl: to Brown. Hoffman and dr Lalla’s classification I.
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Transcript of Ballistocardiograms on trained (unanesthetized) dogs
Abstracts 847
stretched out and the head held upright. From time to
time slight head movements produce minor artefacts. The chicken will generally remain in this position for prolonged periods. The tracing has to be run at high paper speeds (50 or 100 mm./sec.) if details are to be distinguished. The usual parts of the ULF ballisto- cardiogram can be seen in the tracing although they are not c>asily discerned. Keasonable reproducibility is found. The tracing may also be run slowly and pharma- cologically active preparations introduced through a plastic cannula into the large alar (wing) vein without constraining thr ITI,F hallistocardiograph bed.
“I7‘R \*.ow FREQ”ENC\ RALLISTOCARDIOGRAM DURING
BREATHING. H. Kfmsrh, Institute of Physiology, Uni- versity of Bonn, Bonn. Germany.
Ry means of a compensation circuit it is possible to eliminate morr or less completely the respiratory oscil- lations from ULF ballistocardiograms. The output of a ruljber tube respiration recorder with an electronic transducer is mixed with the ballistocardiograph ampli- fi~r output (changed poles) and fed to a third amplifier. It is possible to balance the amplitude of the ballisto- cardiograph and respiration amplifier and to change thr phase in a certain range. After optimal balancing of the amplitudes. phase and time constant, the resultant curve bears little respiratory variation.
\Vith this rquipment one may perform “true” simul- taneous investigations of cardiac output both by ballisto- cardiograms and other methods (direct Fick, Stewart- Hamilton) without regard to possible differences b+ tucen cardiac output in free breathing and when hold- inq thr breath. \Yr are able to get the “physiologic” cardiac output during breathing, which is not in all casts the. samr as in holding the breath. We find the cardiac olltput in basal respiration about 10 per cent higher than while holding the breath. This may be one of the rea- sons .,vhy simultaneous investigations of cardiac output by direct Fick and ballistocardiographic methods differ hy about 10 prr cvnt.
BALLISTOC.ARDIOGRAMS ON TRAINED (UNANESTHETIZED)
DOGS. IVillinm Schwarlz. Dept. of Therapeutic Research. l:nivrrsity of Pennsylvania, Philadelphia, Pa.
‘l‘hat the ultralow frequency ballistocardiographic technic gives fine records on anesthetized dogs has been demonstrated in several laboratories. However, the control rrcords on these animals have often been of a form which. judging from experience with human rec- ords, should be judged as abnormal even though the ballistocardiogram could often be made normal by car- diac stimulation or abdominal compression.
‘This study was designed to answer the question: Is this abnormality of form due to the anesthetic or to some inherrnt difference in cardiac physiology brt\vren man and dog? A small ULF ballistocardiogram, designed fol- animal experiments, was used and acceleration was recorded. Two large dogs were trained for several wc*caks until they would lie still on the instrument. \Yhen good training had been attained, simultaneous ballisto- cardiograms and electrocardiograms were secured. These- records were normal in every respect. One of th<, dogs was then anesthetized by morphine, dialurr- thanc and nembutal. While anesthetized, he gave a record very abnormal by human standards. There:- forr, it seems likely that the abnormality of ballistic
OCTOBER 1960
form so often found in anesthetized dogs is not due to anatomic or physiologic differences betwrcm doq and man but to a true abnormality of cardiac function due either to an advrrse effect of the anesthetic or to the opcr- ative procedure which so often accompanies such cxprri- mrnts.
CARDIAC CONTROI. IN EXERCISE. Ems/ JoXl. .il.l).. Iini- versity of Kentucky, Lexington? Ky.
The current physiologic concept of cardiac control in exercise is based upon newer evidence obtained in experimental studies with normal human subjects. In contrast to observations with the isolated heart or with the heart-lung preparation, size and strokr volume of the human heart adapt themselves during crcrcise in accordance with patterns of the-ir own. Diastolic end volumes become smaller and vrntricular output rises. Thus the seemingly anachronous situation devrlops of a heart reduced in size expellin, cr larg-er stroke voltrmcz. The explanation of this apparent paradox is that resid- ual blood becomes circulating blood. and at the. height of systolk during exercise the cardiac chambers arc almost empty.
At rrst as well as during exercise, tlrca heart of th( athlete is characterized by morphologic and functional features of which the following are relrvant for purposes of this presentation: At rest the athlrtc has a large] heart and uses smaller stroke volumes. During rxercisc his heart becomes smaller than that of the untrained and steps up ventricular output to maximum. In accord- ance with these facts the following ballistocardiographic findings were expected: athletes’ tracings to show Iowrr amplitudes of I-J and K at rest and hishrr amplitudes during exercise.
Data collected in this laboratory during wrll controlled exercise exprriments with trained and untrained sub- jects, all of whom ran a distance of 2 miles. failed to comply with the above hypothrtic postulates. The evidence was presented and alternativr intrrpretations given. The suggestion was made that esistiny theories of cardiac control in exercise rrquire major changes.
BALLISTOCARDIOGRAM IN ACROMEGALY. Jcr:_y I~wXolec. M.D., Medical Academy, Poznan. Poland.
A direct ballistocardiographic method with the use of a resonance hallistocardiograph recording displacement curves was applied. Ballistocardiograms were prr- formed in sixteen patients with acromegaly in the aqr group thirty-six to fifty-seven. In most of these casrs an enlargement of heart volume (Jonsell method) and the prolongation of Q-T interval (rlrctrocardiograrn 1 were found.
The time of the ballistocardiographic waves and th<.il relation to ‘2 and R waves of the simultaneously I‘<*- corded electrocardiographic curve were calculatrd and compared to values obtained in normal subjects. In all acromegalic patients a distinct prolongation of Q-C;, Q-H, Q-I, Q-J and R-H intervals was observed. ?‘hC time of H-I, I-J, J-K, K-L waves did not differ from nor- mal values. In all cases of acromegaly thr coefficient H-K/R-H was diminished (acromcsalv: 1 .‘) 0.29 : normal : 3.3-0.02).
The amplitude of systolic compleves and diastolic waves did not differ significantly in comparison to tllc normal. Variations in the trace during normal br<*ath- ing were found only in six casts (gradI- 2 acccjrdinl: to Brown. Hoffman and dr Lalla’s classification I.
