•
I
CLINICAL INVESTIGATIONS
Nocturnal vs Diurnal Cardiac Arrhythmias in Patients with Chronic Obstructive Pulmonary Disease· Michael R. Flick, M.D.;·· and A
lay Block, M~D., rccr.
Continuous eIec:trocardiop were recorded from ten
patlen" with chroaic oIJstructIve p1IImoImry ...... Dar.... 24 heMIn of reconfill&, tile ....... hreatlled * ; ... for 24 hours, they breathed osypll at 2 L/..... by ..... CaDDuia. Oxyeenation, • mollitorecl by ear omnetric _dies and by periodic aaaIysis of arterial blood, showed
"011-
frequeDt Doctumal de Fluratioa. NiDe ...... stnIted aniaytIaaUs darial the .....utoriD& period, . . the frequellCY of premature veatrJcular COII~ was
Manycausetheories have been proposed regarding the of the high incidence of cardiac arrhythmias in patients with obstructive ventilatory defects, but there is no current agreement with refFor editorial comJDeIIt, see .... 1
erence to cause or treabnent We studied a small selected group of patients with stable severe obstructive disease of the airways, in order to characterize the nature and timing of cardiac arrhythmias, to determine the association of arrhythmias with activity and the status of arterial oxygenation, and to explore the possibility of benefit from therapy with supplemental oxygen at a low rate of flow.
MATERW.S AND METHODS Ten patients with stable chronic obstructive pulmonary disease were chosen for study, with the criteria that their forced expiratory volume in one second (FEV1 •0 ) be Jess that 1.15 L and their FEV 1 . 0 expressed as a percentage of the forced vital capacity (FEVl.o/FVCI) be less than 60 percent. In general, the patients had severe obstructive disease of the airways; the mean FEV 1.0 was 0.76 L, the mean FEVt.ofFVCI was 38 percent, and the mean steady-state carbon monoxide diffusing capacity was 44 percent of the °From the Veterans Administration FIa.
Hospi~
Gainesville,
Supported by the Medical Research Service of the Vet-
erans Administration. Read in part before the American Thoracic Society, New
Orleans, May 18, 1976, and publisbed in abstract form in the American Review of 8e8pirtltof'rl DUeaae (113: 126, 1976) ··Currently Research Fellow, Cardiovascular Research Institute, School of Medicine, University of California, San Francisco. Manuscript received Febl1UllY 27; revision aeeepted May 10. Reprint tequem: Dr. Block, VA H~ GoineioillB, FliwidtJ 32602
8 FUCI, BLOCI
sipifiamtly pater at ....... 'lberapy with S1IppIemeat81 oxygen dramatically reduced the &equeacy of preDl8tllre veDtricular CODtractioas in four patients, but the redactioD in frequeacy of arrhythmias iD the total IfOIIP did Dot reach statistical sipifiamce. 'Ibese results show that cardiac aniaytbmias occur commoaly at .....t d1IriDI sleep iD patients with chronic obstructive pulmoaary disease. The data SOlleR that arterial desataratioD may be respoasibIe for some of these arrhythmias.
values predicted by Bates and associates.' The mean age of the nine men and one woman was 62 years (range, 52 to 83 years). Seven of the patients had been hospitalized in the past for acute respiratory failure. The clinical histories of four patients suggested the diagnosis of cor pulmonale. In addition to chronic obsbuctive pulmonary disease, one patient had diffuse interstitial fibrosis of unknown cause, and one had the pickwickian syndrome. AIl patients were in clinicany stable condition and were studied on the eve of their discharge from the hospital or were brought into the hospital for study. The patients were continuously receiving a wide variety of medications, each of which was maintained throughout the period of study. No patient was receiving continuous therapy with supplemental oxygen, and none received short-term therapy with oxygen in the 48 hours preceding study. Each patient was monitored for 48 hours, an initial 24 hours while breathing room air, followed by 24 hours breathing oxygen at a flow of 2 L/min through a nasal cannula. An indwelling cannula was inserted into the radial artery of each patient and remained in place throughout the monitoring period. Samples of arterial blood for analysis of arterial oxygen tension (Pa02 ), arterial carbon dioxide tension (PaC02 ), and arterial pH were withdrawn frequently from these cannulas and were analyzed immediately. Blood was also drawn at the beginning and end of the 48 hours and was analyzed for hematocrit reading, hemoglobin level, white blood cell count, and levels of sodium, potassium, chloride, carbon dioxide, calcium, blood urea nitrogen, creatinine, and thyroxine iodine (T.). In addition, for the majority of time during the period of study, each patient was attached to an ear oximeter (Hewlett-Packard 4720lA), which allowed continuous recording of arterial oxygen saturation (Sa02 ) . The activity of the patient, administration of drugs, therapies, and symptoms were recorded. A baseline standard 12-lead electrocardiogram was obtained for each patient just before monitoring was begun. During the entire 48-hour period of study, the patient's ECG was recorded continuously on tape by a standard ambulatory electrocardiographic system ( Avionics Electrocardiocorder 425) from a modified V 1 chest lead. The following three systems were used to analyze these tapes for heart rate and
CHEST, 75: 1, JANUARY, 1979
the presence of cardiac anbythmias: (1) real time by printout of the stored tracings on standard electrocardiographic paper; (2) a high-speed (120 times) automatic arrhythmias analyzer (Avionics Electrocardioscan 660); and (3) a scanner that ran at real time. measured each R-R interval on the ECG. stored the measurement, and automatically printed out a sample of each R-R interval occurring more than three times in one hour and a composite histogram of the frequency distribution of R-R intervals at the end of one hour of recording time (Anhythmia Monitor CSAM; 1Dstruments for CaJdiac Research. Inc.). All patients tolerated the monitoring well and were able to sleep and perform normal activities without much difBculty. No patient requested termination of monitoring. and there were no complications or untoward events during the period of study.
REsuLTS We have previously reported in detail the results of the studies of pulmonary function in these patients,"
Baseline ECGs Standard 12-lead ECGs showed normal sinus rhythm in all patients except a single patient with one premature ventricular contraction. In addition, all were characterized by low-voltage, tall P waves and poor progression of R waves across the precordium. Delay in intraventricular conduction was present in three patients (QRS complex more than 0.09 second), and right bundle branch block was seen in one. One patient was believed to have left anterior hemiblock. Baseline ECGs of all patients were "blindly" read by cardiologists as being characteristic of chronic cor pulmonale.
Miscellaneous Laboratory Data Except for three patients whose hematocrit reading was modestly elevated (in the middle 50s), all results for all patients were within normal limits. These laboratory values for the day that the patients breathed room air and the day that they breathed oxygen did not statistically diHer. In the six patients being treated with digoxin, levels of digoxin in the serum ranged from zero to 1.5 ngl ml, with a mean value of 0.4 ngl ml (therapeutic range for our laboratory, 0.8 to 1.6 ng/ml). Comparison of the levels of digoxin during the days that patients breathed room air or oxygen were not statistically diHerent (paired Student's t-test). Arterial Oxygenation We have previously reported the status of arterial oxygenation in these patients during the 48 hours of monitoring," Their baseline SaO, was significantly lower (P < 0.001) during the 24 hours of breathing room air, as opposed to the 24 hours of therapy with supplemental oxygen at a low rate of flow (mean, 86 percent saturation vs 94 percent saturation). All
CHEST, 75: 1, JANUARY, 1979
patients had intermittent episodes of desaturation, often very severe, leading to a Pao, below 40 mID Hg in eight of the ten patients while they breathed room air. These episodes occurred almost exclusively during sleep. S Intermittent desaturation occurred as frequently during the period of breathing oxygen but was never as severe, the Pa
I
CLINICAL INVESTIGATIONS
Nocturnal vs Diurnal Cardiac Arrhythmias in Patients with Chronic Obstructive Pulmonary Disease· Michael R. Flick, M.D.;·· and A
lay Block, M~D., rccr.
Continuous eIec:trocardiop were recorded from ten
patlen" with chroaic oIJstructIve p1IImoImry ...... Dar.... 24 heMIn of reconfill&, tile ....... hreatlled * ; ... for 24 hours, they breathed osypll at 2 L/..... by ..... CaDDuia. Oxyeenation, • mollitorecl by ear omnetric _dies and by periodic aaaIysis of arterial blood, showed
"011-
frequeDt Doctumal de Fluratioa. NiDe ...... stnIted aniaytIaaUs darial the .....utoriD& period, . . the frequellCY of premature veatrJcular COII~ was
Manycausetheories have been proposed regarding the of the high incidence of cardiac arrhythmias in patients with obstructive ventilatory defects, but there is no current agreement with refFor editorial comJDeIIt, see .... 1
erence to cause or treabnent We studied a small selected group of patients with stable severe obstructive disease of the airways, in order to characterize the nature and timing of cardiac arrhythmias, to determine the association of arrhythmias with activity and the status of arterial oxygenation, and to explore the possibility of benefit from therapy with supplemental oxygen at a low rate of flow.
MATERW.S AND METHODS Ten patients with stable chronic obstructive pulmonary disease were chosen for study, with the criteria that their forced expiratory volume in one second (FEV1 •0 ) be Jess that 1.15 L and their FEV 1 . 0 expressed as a percentage of the forced vital capacity (FEVl.o/FVCI) be less than 60 percent. In general, the patients had severe obstructive disease of the airways; the mean FEV 1.0 was 0.76 L, the mean FEVt.ofFVCI was 38 percent, and the mean steady-state carbon monoxide diffusing capacity was 44 percent of the °From the Veterans Administration FIa.
Hospi~
Gainesville,
Supported by the Medical Research Service of the Vet-
erans Administration. Read in part before the American Thoracic Society, New
Orleans, May 18, 1976, and publisbed in abstract form in the American Review of 8e8pirtltof'rl DUeaae (113: 126, 1976) ··Currently Research Fellow, Cardiovascular Research Institute, School of Medicine, University of California, San Francisco. Manuscript received Febl1UllY 27; revision aeeepted May 10. Reprint tequem: Dr. Block, VA H~ GoineioillB, FliwidtJ 32602
8 FUCI, BLOCI
sipifiamtly pater at ....... 'lberapy with S1IppIemeat81 oxygen dramatically reduced the &equeacy of preDl8tllre veDtricular CODtractioas in four patients, but the redactioD in frequeacy of arrhythmias iD the total IfOIIP did Dot reach statistical sipifiamce. 'Ibese results show that cardiac aniaytbmias occur commoaly at .....t d1IriDI sleep iD patients with chronic obstructive pulmoaary disease. The data SOlleR that arterial desataratioD may be respoasibIe for some of these arrhythmias.
values predicted by Bates and associates.' The mean age of the nine men and one woman was 62 years (range, 52 to 83 years). Seven of the patients had been hospitalized in the past for acute respiratory failure. The clinical histories of four patients suggested the diagnosis of cor pulmonale. In addition to chronic obsbuctive pulmonary disease, one patient had diffuse interstitial fibrosis of unknown cause, and one had the pickwickian syndrome. AIl patients were in clinicany stable condition and were studied on the eve of their discharge from the hospital or were brought into the hospital for study. The patients were continuously receiving a wide variety of medications, each of which was maintained throughout the period of study. No patient was receiving continuous therapy with supplemental oxygen, and none received short-term therapy with oxygen in the 48 hours preceding study. Each patient was monitored for 48 hours, an initial 24 hours while breathing room air, followed by 24 hours breathing oxygen at a flow of 2 L/min through a nasal cannula. An indwelling cannula was inserted into the radial artery of each patient and remained in place throughout the monitoring period. Samples of arterial blood for analysis of arterial oxygen tension (Pa02 ), arterial carbon dioxide tension (PaC02 ), and arterial pH were withdrawn frequently from these cannulas and were analyzed immediately. Blood was also drawn at the beginning and end of the 48 hours and was analyzed for hematocrit reading, hemoglobin level, white blood cell count, and levels of sodium, potassium, chloride, carbon dioxide, calcium, blood urea nitrogen, creatinine, and thyroxine iodine (T.). In addition, for the majority of time during the period of study, each patient was attached to an ear oximeter (Hewlett-Packard 4720lA), which allowed continuous recording of arterial oxygen saturation (Sa02 ) . The activity of the patient, administration of drugs, therapies, and symptoms were recorded. A baseline standard 12-lead electrocardiogram was obtained for each patient just before monitoring was begun. During the entire 48-hour period of study, the patient's ECG was recorded continuously on tape by a standard ambulatory electrocardiographic system ( Avionics Electrocardiocorder 425) from a modified V 1 chest lead. The following three systems were used to analyze these tapes for heart rate and
CHEST, 75: 1, JANUARY, 1979
the presence of cardiac anbythmias: (1) real time by printout of the stored tracings on standard electrocardiographic paper; (2) a high-speed (120 times) automatic arrhythmias analyzer (Avionics Electrocardioscan 660); and (3) a scanner that ran at real time. measured each R-R interval on the ECG. stored the measurement, and automatically printed out a sample of each R-R interval occurring more than three times in one hour and a composite histogram of the frequency distribution of R-R intervals at the end of one hour of recording time (Anhythmia Monitor CSAM; 1Dstruments for CaJdiac Research. Inc.). All patients tolerated the monitoring well and were able to sleep and perform normal activities without much difBculty. No patient requested termination of monitoring. and there were no complications or untoward events during the period of study.
REsuLTS We have previously reported in detail the results of the studies of pulmonary function in these patients,"
Baseline ECGs Standard 12-lead ECGs showed normal sinus rhythm in all patients except a single patient with one premature ventricular contraction. In addition, all were characterized by low-voltage, tall P waves and poor progression of R waves across the precordium. Delay in intraventricular conduction was present in three patients (QRS complex more than 0.09 second), and right bundle branch block was seen in one. One patient was believed to have left anterior hemiblock. Baseline ECGs of all patients were "blindly" read by cardiologists as being characteristic of chronic cor pulmonale.
Miscellaneous Laboratory Data Except for three patients whose hematocrit reading was modestly elevated (in the middle 50s), all results for all patients were within normal limits. These laboratory values for the day that the patients breathed room air and the day that they breathed oxygen did not statistically diHer. In the six patients being treated with digoxin, levels of digoxin in the serum ranged from zero to 1.5 ngl ml, with a mean value of 0.4 ngl ml (therapeutic range for our laboratory, 0.8 to 1.6 ng/ml). Comparison of the levels of digoxin during the days that patients breathed room air or oxygen were not statistically diHerent (paired Student's t-test). Arterial Oxygenation We have previously reported the status of arterial oxygenation in these patients during the 48 hours of monitoring," Their baseline SaO, was significantly lower (P < 0.001) during the 24 hours of breathing room air, as opposed to the 24 hours of therapy with supplemental oxygen at a low rate of flow (mean, 86 percent saturation vs 94 percent saturation). All
CHEST, 75: 1, JANUARY, 1979
patients had intermittent episodes of desaturation, often very severe, leading to a Pao, below 40 mID Hg in eight of the ten patients while they breathed room air. These episodes occurred almost exclusively during sleep. S Intermittent desaturation occurred as frequently during the period of breathing oxygen but was never as severe, the Pa
