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Life-threatening alterations in heart rate after the use of adenosine in atrial flutter
IN CONSULTATION patients is much greater. Because 40 ECGs were obtained while taking placebo in each participant, the spontaneous variability in QTc interval with placebo was also described. Only one of the 20 normal subjects had a mean baseline QTc ~440 msec, yet 14 of the 28 normal subjects had at least one of the 40 placebo ECGs with a QTc 2440 msec. The 20 patients with cardiovascular disease had a mean QTc at baseline of 417 msec; yet 20 of 28 had at least one ECG on placebo with a QTc interval ~440 msec. On the average, the QTc fluctuated 56 msec in each patient during placebo administration. From the observed placebo variability, we calculated that an increase in QTc of 135 msec while receiving drug therapy is likely to represent a drug effect at the 95% confidence interval.
Life-Threatening Alterations in Heart Rate After the Use of Adenosine in Atrial Flutter MA, Brodslq, C. Hwang, D. Hunter, P.-S. Chen, D. Smith, H. Ariani, W.D. Johnston, B.J. Allen, J.G. Chun, CR. Gold. Department of Medicine, Division of Cardiology, University of California-Irvine Medical Center, Orange, CA. Am Heart J 1995;130: 564-71.
Adenosine has become the preferred treatment for common types of supraventricular tachycardia because it is extremely effective and rarely associated with serious side effects. It has also been advocated as an intervention for diagnostic use to assess uncommon types of tachycardia. Evidence is shown in this report that adenosine was associated with dangerous worsening of arrhythmia in patients with atria1 flutter. In two patients, adenosine precipitated acceleration of ventricular response, in one case necessitating emergent cardioversion. Both patients had atria1 flutter with 2 to 1 atrioventricular block that evolved into 1 to 1 atrioventricular conduction. In three other patients, adenosine was associated with prolonged bradyasystole and hypotension. In each of the five patients, adenosine was given in a standard fashion (6 or 12 mg). In summary, adenosine should be recognized as a potentially dangerous intervention in patients with atria1 flutter. If it is used for diagnostic purposes, resuscitative equipment should be readily available.
Renal Insufficiency: Gadopentetate Dimeglumine as a Radiographic Contrast Agent During Peripheral Vascular Interventional Procedures JA. Raufman, S.C. Geller, AC. Waltman. Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, HA. Radiology 1996;198:579-81.
Gadopentetate dimeglumine diluted 1:l with 0.9% normal saline was used as the radiographic contrast agent in two patients with azotemia who underwent peripheral vascular interventional procedures. The patients had no evidence of contrast material-induced renal failure after the procedures. The radiographic attenuation of the diluted gadopentetate dimeglumine was equivalent to diatrizoate meglumine diluted in 40 mg iodine per milliliter. Gadopentetate dimeglumine is an alternative radiographic contrast material for azotemic patients.
Dose-Response Relation Between Terfenadine (Seldane) and the QTc Interval on the Scalar Electrocardiogram: Distinguishing a Drug Effect From Spontaneous Variability CM. Pratt, 5. Ruberg, J. Morganroth, B. McNutt J. Woodward, 5. Harris, J. Ruskin, L Moye. Baylor College of Medicine, Houston, TX. Am Heart ] 1996;13 l:472--80.
Risk of Gastrointestinal Haemorrhage Calcium Antagonists in Hypertensive 67 Years Old
The primary goal of this investigation was to describe the effect of terfenadine on the QT interval corrected for heart rate (QTc) of the scalar electrocardiogram (ECG). The design was double-blind, four-period crossover, dose escalation, which involved 28 normal healthy volunteers and 28 patients with stable cardiovascular disease. At baseline, the normal subjects had a mean QTc interval of 407 msec, whereas the patients with cardiovascular disease had a mean QTc interval of 4 17 msec (p < 0.0 1). The largest increase in mean QTc on terfenadine was 24 msec in a normal subject and 28 msec in a patient with cardiovascular disease. The longest average QTc observed was 449 msec and 501 msec in any normal subject and patient with cardiovascular disease, respectively. Compared to baseline, terfenadine 60 mg twice daily is associated with a QTc increase of 6 msec in normal subjects and a 12 msec increase in patients with cardiovascular disease (p < 0.01 vs baseline; p > 0.05 when the two populations were compared). Although the QTc increases from baseline are statistically significant, the magnitude of the spontaneous variability in QTc in the same KC
CURRENT
JOURNAL
With Persons
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H. Pahor, J.H. Guralnik, C.D. Furberg, P. Carbonin, R.J. Havlik. lstituto Hedicina lntema Geriatria, Univenita Cattolica del Sacro Cuore, Rome, Italy. Lancet 1996347: 1061-5.
Background: Calcium antagonists are used frequently in management of hypertension. In addition to their cardiovascular effects, these drugs inhibit platelet aggregation. Therefore we examined whether the use of calcium antagonists was associated with an increased risk of gastrointestinal haemorrhage (GIH). Methods: A prospective cohort study was conducted from 1985 through 1992 on 1636 hypertensive persons aged 968 years living in three communities. The participants were taking beta-blockers, angiotensinconverting enzyme (ACE) inhibitors, or calcium antagonists; those taking combinations of these drugs were excluded. The incidence of GIH was assessed by surveying hospital discharge diagnoses and deaths, Age, gender, disability, arterial pressure, other drugs, and comorbid conditions were examined as confounders. Findings: Compared with
REVIEW
62
November/Decembei
1996
Life-Threatening Alterations in Heart Rate After the Use of Adenosine in Atrial Flutter MA, Brodslq, C. Hwang, D. Hunter, P.-S. Chen, D. Smith, H. Ariani, W.D. Johnston, B.J. Allen, J.G. Chun, CR. Gold. Department of Medicine, Division of Cardiology, University of California-Irvine Medical Center, Orange, CA. Am Heart J 1995;130: 564-71.
Adenosine has become the preferred treatment for common types of supraventricular tachycardia because it is extremely effective and rarely associated with serious side effects. It has also been advocated as an intervention for diagnostic use to assess uncommon types of tachycardia. Evidence is shown in this report that adenosine was associated with dangerous worsening of arrhythmia in patients with atria1 flutter. In two patients, adenosine precipitated acceleration of ventricular response, in one case necessitating emergent cardioversion. Both patients had atria1 flutter with 2 to 1 atrioventricular block that evolved into 1 to 1 atrioventricular conduction. In three other patients, adenosine was associated with prolonged bradyasystole and hypotension. In each of the five patients, adenosine was given in a standard fashion (6 or 12 mg). In summary, adenosine should be recognized as a potentially dangerous intervention in patients with atria1 flutter. If it is used for diagnostic purposes, resuscitative equipment should be readily available.
Renal Insufficiency: Gadopentetate Dimeglumine as a Radiographic Contrast Agent During Peripheral Vascular Interventional Procedures JA. Raufman, S.C. Geller, AC. Waltman. Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, HA. Radiology 1996;198:579-81.
Gadopentetate dimeglumine diluted 1:l with 0.9% normal saline was used as the radiographic contrast agent in two patients with azotemia who underwent peripheral vascular interventional procedures. The patients had no evidence of contrast material-induced renal failure after the procedures. The radiographic attenuation of the diluted gadopentetate dimeglumine was equivalent to diatrizoate meglumine diluted in 40 mg iodine per milliliter. Gadopentetate dimeglumine is an alternative radiographic contrast material for azotemic patients.
Dose-Response Relation Between Terfenadine (Seldane) and the QTc Interval on the Scalar Electrocardiogram: Distinguishing a Drug Effect From Spontaneous Variability CM. Pratt, 5. Ruberg, J. Morganroth, B. McNutt J. Woodward, 5. Harris, J. Ruskin, L Moye. Baylor College of Medicine, Houston, TX. Am Heart ] 1996;13 l:472--80.
Risk of Gastrointestinal Haemorrhage Calcium Antagonists in Hypertensive 67 Years Old
The primary goal of this investigation was to describe the effect of terfenadine on the QT interval corrected for heart rate (QTc) of the scalar electrocardiogram (ECG). The design was double-blind, four-period crossover, dose escalation, which involved 28 normal healthy volunteers and 28 patients with stable cardiovascular disease. At baseline, the normal subjects had a mean QTc interval of 407 msec, whereas the patients with cardiovascular disease had a mean QTc interval of 4 17 msec (p < 0.0 1). The largest increase in mean QTc on terfenadine was 24 msec in a normal subject and 28 msec in a patient with cardiovascular disease. The longest average QTc observed was 449 msec and 501 msec in any normal subject and patient with cardiovascular disease, respectively. Compared to baseline, terfenadine 60 mg twice daily is associated with a QTc increase of 6 msec in normal subjects and a 12 msec increase in patients with cardiovascular disease (p < 0.01 vs baseline; p > 0.05 when the two populations were compared). Although the QTc increases from baseline are statistically significant, the magnitude of the spontaneous variability in QTc in the same KC
CURRENT
JOURNAL
With Persons
Over
H. Pahor, J.H. Guralnik, C.D. Furberg, P. Carbonin, R.J. Havlik. lstituto Hedicina lntema Geriatria, Univenita Cattolica del Sacro Cuore, Rome, Italy. Lancet 1996347: 1061-5.
Background: Calcium antagonists are used frequently in management of hypertension. In addition to their cardiovascular effects, these drugs inhibit platelet aggregation. Therefore we examined whether the use of calcium antagonists was associated with an increased risk of gastrointestinal haemorrhage (GIH). Methods: A prospective cohort study was conducted from 1985 through 1992 on 1636 hypertensive persons aged 968 years living in three communities. The participants were taking beta-blockers, angiotensinconverting enzyme (ACE) inhibitors, or calcium antagonists; those taking combinations of these drugs were excluded. The incidence of GIH was assessed by surveying hospital discharge diagnoses and deaths, Age, gender, disability, arterial pressure, other drugs, and comorbid conditions were examined as confounders. Findings: Compared with
REVIEW
62
November/Decembei
1996