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Pizzale S, Gollob MH, Gow R, Birnie DH. Sudden death in a young man with catecholaminergic polymorphic ventricular tachycardia and paroxysmal atrial fibrillation. J Cardiovasc Electrophysiol 2008; 19:1319-21. [PMID: 18554199 DOI: 10.1111/j.1540-8167.2008.01211.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial condition that presents with exercise-induced syncope or sudden death in children or young adults. In most cases the disease is caused by a mutation in the cardiac ryanodine receptor (RyR2) gene. Current evidence suggests that primary therapy for CPVT is beta blockade and implantable cardioverter defibrillator (ICD) placement. There is a recent report of a patient with CPVT who died despite appropriate ICD therapies, and we report a similar case. Our patient died after probably initially receiving inappropriate ICD shocks for atrial fibrillation. We recommend that utmost efforts should be made to prevent shocks including repeated exercise testing to confirm suppression of PVT.
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Krahn AD, Champagne J, Healey JS, Cameron D, Simpson CS, Thibault B, Mangat I, Tung S, Sterns L, Birnie DH, Exner DV, Parkash R, Sivakumaran S, Davies T, Coutu B, Crystal E, Wolfe K, Verma A, Stephenson EA, Sanatani S, Gow R, Connors S, Paredes FA, Essebag V. Outcome of the Fidelis implantable cardioverter-defibrillator lead advisory: A report from the Canadian Heart Rhythm Society Device Advisory Committee. Heart Rhythm 2008; 5:639-42. [DOI: 10.1016/j.hrthm.2008.01.029] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Accepted: 01/21/2008] [Indexed: 10/22/2022]
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153
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Rutberg J, Green MS, Gow RM, Geraghty MT, Honeywell C, Ewen J, Birnie DH, Tang A, Lemery R, Gollob MH. Molecular autopsy in the sudden cardiac death of a young woman: a first Canadian report. Can J Cardiol 2007; 23:904-6. [PMID: 17876385 PMCID: PMC2651371 DOI: 10.1016/s0828-282x(07)70849-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Standard autopsy of young victims with sudden cardiac death commonly does not identify a specific pathological diagnosis. In such cases, sudden cardiac death may be secondary to a genetic condition predisposing the patient to ventricular arrhythmias. Failure to identify a genetic etiology for an unexpected sudden death may leave surviving family members at risk for a similar tragedy. The case of a 21-year-old woman who died suddenly while at rest is presented. Molecular genetic analysis of tissue retrieved from the regional coroner's office identified a novel missense mutation in the KCNH2 gene, a gene known to cause the long QT syndrome.
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Birnie DH, Sambell C, Johansen H, Williams K, Lemery R, Green MS, Gollob MH, Lee DS, Tang ASL. Use of implantable cardioverter defibrillators in Canadian and US survivors of out-of-hospital cardiac arrest. CMAJ 2007; 177:41-6. [PMID: 17606938 PMCID: PMC1896034 DOI: 10.1503/cmaj.060730] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Cardiac arrest due to ventricular arrhythmia in the absence of a reversible cause or contraindication has been a class I indication for insertion of an implantable cardioverter defibrillator since 1998. We compared and contrasted the use of implantable cardioverter defibrillator therapy in Canada and the United States among adults who survived a cardiac arrest. METHOD Data on hospital separations from April 1, 1994 through March 31, 2003 were obtained from the Health Person-Oriented Information Database maintained by Statistics Canada and from the US National Hospital Discharge Survey on all patients with a primary diagnosis of cardiac arrest, ventricular fibrillation or ventricular flutter for the same 9-year period. We excluded all records of patients with a secondary diagnosis of acute myocardial infarction. RESULTS In Canada, 3793 patients survived to discharge after a cardiac arrest; 628 (16.6%) of these were implanted with a cardioverter defibrillator before discharge. The implant rate rose steadily from 5.4% in 1994/95 to 26.7% in 2002/03. In the United States, 23 688 (30.2%) of 78 538 such survivors received an implantable cardioverter defibrillator before discharge. Logistic regression analysis indicated that sex, age, fiscal year, the hospital's teaching status, hospital size and patient history of heart failure were positive predictors of implantable cardioverter defibrillator implantation. Age, renal failure, liver failure and cancer were negative predictors of receiving an implantable cardioverter defibrillator. INTERPRETATION The rate of use of implantable cardioverter defibrillator therapy for cardiac arrest survivors in Canada is increasing, but still is lower than the rate in the United States.
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Birnie DH, Tang ASL. If It Is Not Broken, Don't Fix It: Avoidance of Right Ventricular Pacing in Cardiac Resynchronization Therapy. J Cardiovasc Electrophysiol 2007; 18:505-6. [PMID: 17403083 DOI: 10.1111/j.1540-8167.2007.00799.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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156
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Davis DR, Lemery R, Green M, Gollob MH, Tang ASL, Birnie DH. Transient left ventricular apical ballooning following a prolonged ablation. J Interv Card Electrophysiol 2007; 17:47-9. [PMID: 17226085 DOI: 10.1007/s10840-006-9051-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Accepted: 10/15/2006] [Indexed: 10/23/2022]
Abstract
The authors report a case of transient left ventricular apical ballooning after a prolonged electrophysiology procedure. Interventional electrophysiologists should be aware of this syndrome as a potential complication.
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157
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Davis DR, Tang AS, Birnie DH, Gollob MH. Successful ablation of a concealed parahisian accessory pathway using a remote magnetic navigation system following failure by conventional methods. J Interv Card Electrophysiol 2006; 16:149-51. [PMID: 17109208 DOI: 10.1007/s10840-006-9040-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Accepted: 08/02/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Using conventional catheters, ablation of concealed parahisian accessory pathways may be difficult and high risk for heart block. METHODS AND RESULTS We describe the case of a concealed parahisian accessory pathway with three prior attempts to ablate using conventional methods (RF and cryotherapy). Using a remote magnetic navigation system, successful ablation occurred following a single RF lesion (total fluoroscopy time 17 min). In contrast to previous attempts, the patient remained asymptomatic during follow-up (12 months). CONCLUSIONS This is the first report of successful remote magnetic catheter ablation of a concealed parahisian AP. Magnetic catheter stability during RF application likely contributed to the success of this procedure and may have minimized the risk of AV block.
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Davis DR, Tang ASL, Lemery R, Green MS, Gollob MH, Birnie DH. Influence of gender on ICD implantation for primary and secondary prevention of sudden cardiac death. ACTA ACUST UNITED AC 2006; 8:1054-6. [PMID: 17101630 DOI: 10.1093/europace/eul123] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AIMS This study sought to investigate the influence of gender on access to ICD therapy and examine the influence of gender on subsequent ICD shock experience. METHODS AND RESULTS The records of 353 consecutive patients (140 and 213 secondary prevention, respectively) who received their first ICD between January 2000 and March 2004 were reviewed. All patients fulfilled criteria for primary or secondary prevention ICD implantation. Baseline characteristics and ICD shock experiences were compared. Female patients were younger and less likely to have a history of ischaemic heart disease or atrial arrhythmias (P<0.01). In contrast, female patients were more likely to have heart failure and diabetes (P<0.01). Markedly fewer females received an ICD for either primary (M:F ratio 8.5:1, P<0.01) or secondary (M:F ratio 4.5:1, P<0.01) prevention. Further, significantly fewer female patients received an ICD for MADIT II indications (M:F 11.2:1, P<0.01). Over the mean follow-up of 1.8+/-1.1 years, gender had no influence upon the likelihood of receiving either an appropriate or an inappropriate shock (P=ns). CONCLUSION Although male patients accounted for the great majority (85%) of all ICD recipients, there was no evidence of influence of gender on the likelihood of receiving an appropriate or inappropriate shock.
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Davis DR, Gollob MH, Green MS, Lemery R, Tang AS, Birnie DH. Appropriate Result from an Inappropriate ICD Shock. Pacing Clin Electrophysiol 2006; 29:1183-4. [PMID: 17038153 DOI: 10.1111/j.1540-8159.2006.00514.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A case of inappropriate detection of an ungrounded external AC current by an implantable cardioverter defibrillator (ICD) is reported. The resultant ICD shock dislodged the patient from the electrical source, thus preventing injury or electrocution.
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Abstract
PURPOSE OF REVIEW Atrial fibrillation is the most common clinical arrhythmia. Current treatment strategies are far from optimal. One new research direction is to target the atrial fibrillation substrate and to examine whether drugs can produce atrial structural and/or electrophysiological remodeling and whether this results in a reduction in atrial fibrillation burden. RECENT FINDINGS Two prospective randomized studies have shown that the addition of an angiotensin converting enzyme inhibitor or an angiotensin receptor blocker to amiodarone reduces the recurrence rate of atrial fibrillation after electrical cardioversion. There are ten completed prospective clinical trials with atrial fibrillation as a secondary endpoint or assessed in post-hoc analysis. Five of these studies have reported a positive impact of angiotensin converting enzyme inhibitors or angiotensin receptor blockers on atrial fibrillation burden. A meta-analysis showed that active drugs reduced the overall risk of development of atrial fibrillation by 28%. Patients in the heart failure trials obtained most benefit from these drugs (relative risk reduction 44%, P = 0.07). SUMMARY The initial basic science and clinical trial data suggest that modulation of the renin angiotensin system may be an effective treatment for atrial fibrillation. The following, however, remain to be clarified: do these drugs have a clinically meaningful impact on atrial fibrillation burden; if there is an impact, is it similar in all atrial fibrillation patients or just in certain subsets; do angiotensin converting enzyme inhibitors and angiotensin receptor blockers have similar benefits; and is there a role for aldosterone antagonists?
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161
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Mielniczuk LM, Williams K, Davis DR, Tang ASL, Lemery R, Green MS, Gollob MH, Haddad H, Birnie DH. Frequency of peripartum cardiomyopathy. Am J Cardiol 2006; 97:1765-8. [PMID: 16765131 DOI: 10.1016/j.amjcard.2006.01.039] [Citation(s) in RCA: 196] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Revised: 01/09/2006] [Accepted: 01/09/2006] [Indexed: 11/26/2022]
Abstract
Reports from case series have estimated the incidence of peripartum cardiomyopathy (PC) at 1 case/1,485 live births to 1 case/15,000 live births and probable mortality rates of 7% to 60%. The objective of this study was to produce the first population-based study of the incidence, mortality, and risk factors for PC. The National Hospital Discharge Survey was used. Discharge information was available for 3.6 million patient discharges from 1990 to 2002. There were an estimated 16,296 cases of PC from 1990 to 2002. During this period, there were 51,966,560 live births in the United States. Thus, the incidence of PC was 1 case/3,189 live births. There was a trend toward an increase in PC incidence during the study period, with an estimate for the years 2000 to 2002 of 1 case/2,289 live births. The in-hospital mortality rate was 1.36% (95% confidence interval 0% to 10.2%). The total mortality rate was 2.05% (95% confidence interval 0.29% to 10.8%). Patients with PC were older (mean age 29.7 vs 26.9 years), were more likely to be black (32.2% vs 15.7%), and had a higher incidence of pregnancy associated hypertensive disorders (22.5% vs 5.87%) compared with national data. In conclusion, the incidence of PC is relatively uncommon, occurring at an average frequency of 1 case/3,189 live births from 1990 to 2002. The estimated mortality of 1.36% to 2.05% (95% confidence interval 0.29% to 10.8%) is less than previously reported from most case series.
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Davis DR, Birnie DH, Tang AS, Samie R, Al-Rawahi N, Green MS, Gollob MH. P4-112. Heart Rhythm 2006. [DOI: 10.1016/j.hrthm.2006.02.767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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163
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Davis DR, Huang H, Green MS, Gow R, Birnie DH, Tang AS, Rutberg J, Honeywell C, Chahine M, Gollob MH. AB47-6. Heart Rhythm 2006. [DOI: 10.1016/j.hrthm.2006.02.299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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164
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Birnie DH, Sambell C, Williams K, Johansen H, Green MS, Gollob MH, Tang AS, Lee D. P2-46. Heart Rhythm 2006. [DOI: 10.1016/j.hrthm.2006.02.458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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165
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Samie R, Davis DR, Birnie DH, Green MS, Rawahi NA, Tang AS, Gollob MH. AB11-3. Heart Rhythm 2006. [DOI: 10.1016/j.hrthm.2006.02.084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
PURPOSE OF REVIEW Cardiac resynchronization therapy improves quality of life, exercise performance, left ventricular ejection fraction, and reduces heart failure hospitalizations and mortality in patients with New York Heart Association class III or IV congestive heart failure and intraventricular conduction delay. A number of key clinical research questions remain, perhaps most importantly the issue of why apparently suitable patients do not respond to cardiac resynchronization therapy. These issues are also relevant to patients who do respond to cardiac resynchronization therapy as potentially their response might be further increased. This article will review the data regarding the frequency of the problem of non-response to cardiac resynchronization therapy and then discuss the postulated reasons and potential solutions. RECENT FINDINGS Rates of non-response to cardiac resynchronization therapy are often quoted as 20-30%, but a critical analysis of the data would suggest the true non-responder rate can be estimated as perhaps 40-50%. The data indicate that on a population basis non-response is multi-factorial and the extent of mechanical dyssynchrony, left ventricular pacing site and cause of congestive heart failure are likely to be important. Ongoing research is exploring the utility of various techniques for quantifying mechanical dyssynchrony and the potential benefits of targeted left ventricular lead placement and post-implant optimization. SUMMARY Cardiac resynchronization therapy is a major breakthrough in treatment for advanced congestive heart failure patients. There is substantial rate of non-response to this therapy, however, and research is exploring various ways to increase the response to the technique.
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167
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Lau EW, Birnie DH. One heart, two minds. Europace 2005; 7:535-6. [PMID: 16216753 DOI: 10.1016/j.eupc.2005.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 05/30/2005] [Accepted: 06/20/2005] [Indexed: 10/25/2022] Open
Abstract
A case of complex atrial tachyarrhythmias following orthotopic heart transplantation is presented. The ablation strategy in such a situation and the outcome achieved are discussed.
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Birnie DH, Vickers LE, Hillis WS, Norrie J, Cobbe SM. Increased titres of anti-human heat shock protein 60 predict an adverse one year prognosis in patients with acute cardiac chest pain. Heart 2005; 91:1148-53. [PMID: 16103543 PMCID: PMC1769094 DOI: 10.1136/hrt.2004.040485] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To assess whether antibodies to human heat shock protein 60 (anti-huhsp60) or to mycobacterial heat shock protein 65 (anti-mhsp65) predict an adverse one year prognosis in patients admitted with acute cardiac chest pain. DESIGN Prospective observational study. SETTING Teaching hospital. PATIENTS 588 consecutive emergency admissions of patients with acute chest pain of suspected cardiac origin. MAIN OUTCOME MEASURES Anti-huhsp60 and anti-mhsp65 titres were assayed on samples drawn on the morning after admission. The end points after discharge were coronary heart disease death, non-fatal myocardial infarction, coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, angiogram, or readmission with further cardiac ischaemic chest pain. RESULTS During follow up after discharge (mean of 304 days, range 1-788 days), 277 patients had at least one of the study outcomes. Patients with increased titres of anti-huhsp60 had an adverse prognosis (hazard ratio 1.56 (95% confidence interval 1.09 to 2.23) comparing highest versus lowest quartiles, p = 0.015). Anti-mhsp65 titres were not predictive. CONCLUSIONS Patients admitted with acute cardiac chest pain and increased titres of anti-huhsp60 had an adverse one year prognosis.
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169
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Davis DR, Krahn AD, Tang ASL, Lemery R, Green MS, Gollob M, Yee R, Skanes AC, Klein GJ, Birnie DH. Long-term outcome of cardiac resynchronization therapy in patients with severe congestive heart failure. Can J Cardiol 2005; 21:413-7. [PMID: 15861258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
BACKGROUND Cardiac resynchronization therapy (CRT) has recently been shown to be an effective short-term therapy for patients with drug-refractory heart failure and intraventricular conduction delay. Little is known about the long-term effects of this therapy. OBJECTIVES To determine the long-term outcome of all consecutive patients who underwent CRT at two Canadian centres, and to determine what baseline variables predict a response to CRT. RESULTS AND CONCLUSIONS The present study comprised a total of 85 patients (mean age 66+/-9 years; 88% male) with New York Heart Association class II (4%), class III (84%) or class IV (12%) heart failure. All patients fulfilled the standard CRT indications with a QRS duration of 168+/-22 ms and a nuclear gated ejection fraction (EF) of 21+/-6%. Eighteen of the 85 patients were implanted with a combination automatic implantable cardioverter-defibrillator and CRT device. Within a mean clinical follow-up of 3.0+/-1.0 years, 26 of the 85 patients died, and eight patients underwent cardiac transplantation, with four transplant-related deaths (mean survival 3.53+/-0.26 years). Ten patients died of sudden cardiac death, eight patients died of progressive heart failure and eight patients died of noncardiac causes. None of the baseline factors (age, sex, EF, etiology, New York Heart Association class, QRS duration or implantable cardioverter-defibrillator) or indexes of CRT (change in EF or QRS duration) were predictive of a poor outcome. There was a clear trend for patients with a greater left ventricular EF gain to have a better outcome (P=0.1). The present observational data represent one of the longest follow-up databases of patients undergoing CRT. The significant morbidity and mortality found after CRT highlight the severity of the underlying cardiac pathology and concurrent illnesses.
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170
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Lau EW, Birnie DH, Lemery R, Tang ASL, Green MS. Acupuncture triggering inappropriate ICD shocks. Europace 2005; 7:85-6. [PMID: 15670973 DOI: 10.1016/j.eupc.2004.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2004] [Accepted: 05/04/2004] [Indexed: 11/21/2022] Open
Abstract
Acupuncture is a modality of alternative medicine popular certain sectors of society. The possible interaction between acupuncture and ICD therapy has not been previously investigated. A case of acupuncture triggering inappropriate shocks from the ICD is reported.
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Lau EW, Green MS, Birnie DH, Lemery R, Tang ASL. Ventricular Tachycardia Terminated by an ICD:. Is There More Than What Meets the Eye? Pacing Clin Electrophysiol 2004; 27:1656-8. [PMID: 15613130 DOI: 10.1111/j.1540-8159.2004.00700.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lau EW, Green MS, Birnie DH, Lemery R, Tang ASL. Preexcitation masking underlying aberrant conduction: An atriofascicular accessory pathway functioning as an ectopic right bundle branch. Heart Rhythm 2004; 1:497-9. [PMID: 15851206 DOI: 10.1016/j.hrthm.2004.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Accepted: 06/16/2004] [Indexed: 11/29/2022]
Abstract
Preexcitation and aberrant conduction both cause a broad QRS complex. An unusual case of an atriofascicular accessory pathway effectively functioning as an ectopic right bundle branch and responsible for both physiologically normal ventricular activation and pathologic preexcited tachycardias as part of a split AV node-bundle branch system is presented.
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173
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Walker NL, Cobbe SM, Birnie DH. Tachycardiomyopathy: a diagnosis not to be missed. BRITISH HEART JOURNAL 2004; 90:e7. [PMID: 14729812 PMCID: PMC1768059 DOI: 10.1136/hrt.2003.017129] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The prognosis of dilated cardiomyopathy is generally poor. In the vast majority of cases the cause of the ventricular dysfunction is irreversible but occasionally potentially curable causes are identified. Tachycardiomyopathy is a rare and potentially treatable cause of heart failure. A patient with a particularly severe case who had an excellent outcome is presented.
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Birnie DH, Vickers LE, Hillis S, Norrie J, Cobbe SM. Elevated titre of antihuman shock protein 60 predicts an adverse medium-term prognosis in patients with unstable angina. J Am Coll Cardiol 2003. [DOI: 10.1016/s0735-1097(03)81106-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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176
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Swan L, Birnie DH, Padmanabhan S, Inglis G, Connell JMC, Hillis WS. The genetic determination of left ventricular mass in healthy adults. Eur Heart J 2003; 24:577-82. [PMID: 12643891 DOI: 10.1016/s0195-668x(02)00524-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
AIMS The extent to which left ventricular (LV) mass, an independent cardiovascular risk factor, is determined by genetic factors is unclear. The aim of this study was to assess the heritability of LV mass and its association with three potential candidate genes. METHODS A population-based adult twin study model was utilized. Echocardiographic assessment of LV mass was performed in 110 twin pairs (mean age 55.9+/-10.9 years). An estimate of genetic determination, heritability, was calculated for the main echocardiographic parameters. The cohort were genotyped for the G-protein beta-3, aldosterone synthase, and beta-1 adrenoceptor genes. RESULTS The intra-class correlation coefficients for LV mass were 0.69 for monozygotic (r-MZ) twins and 0.32 for dizygotic (r-DZ) twins, P=0.008 (heritability estimate of 0.69). This pattern persisted following correction for known confounding factors. Within-pair differences in the monozygotic, discordant and concordant dizygotic twins showed no differences for the three genes with respect to left ventricular wall thickness or mass. There was a non-significant trend towards a relationship between LV mass and the beta-1 adrenoceptor genotype. CONCLUSION Within a normal population left ventricular mass has a significant genetic determination. Further investigation of potential candidate genes is required.
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Swan L, Birnie DH, Inglis G, Connell JMC, Hillis WS. The determination of carotid intima medial thickness in adults--a population-based twin study. Atherosclerosis 2003; 166:137-41. [PMID: 12482560 DOI: 10.1016/s0021-9150(02)00317-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Although cardiovascular events are known to cluster in families it is unclear the extent to which atherosclerosis per se is genetically determined. The aim of this study was to assess the heritability of carotid intima media thickness (IMT) measurements, a surrogate marker of early atherosclerosis, using a population-based twin study methodology. METHODS B-mode carotid artery ultrasound images were acquired on 264 twin subjects (142 monozygotic (MZ); mean age 54.3 years and 122 dizygotic (DZ); mean age 51.7 years). An estimate of genetic determination, heritability, was calculated for the IMT parameters before and after correction for confounding variables. RESULTS An increased carotid IMT was associated with known cardiovascular risk factors (total cholesterol r=0.24, P<0.001 and systolic blood pressure r=0.42, P<0.001) and with a history of coronary events (0.79+/-0.12 vs. 0.72+/-0.14, P=0.01). Carotid IMT measurements demonstrated a familial influence (intra-class correlation of 0.54 for MZ vs. 0.39 for DZ) but no specific genetic determination (heritability estimate 0.31, P=0.15). CONCLUSION Within a normal population carotid IMT is under a familial, but not genetic influence. The mechanism of genetic control over cardiovascular events may not be mediated through atherosclerotic load as measured by IMT.
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Birnie DH, Cobbe SM. Risk of sudden death after discharge following myocardial infarction. Eur Heart J 2001; 22:1153-5. [PMID: 11440487 DOI: 10.1053/euhj.2001.2683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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179
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Swan L, Hood S, Birnie DH, Muir DF, McCann GP, Hillis WS. The haemodynamic effect of the 5HT1 agonist BMS-180048: a class effect of triptans? Br J Clin Pharmacol 1999; 47:189-94. [PMID: 10190654 PMCID: PMC2014163 DOI: 10.1046/j.1365-2125.1999.00875.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS To investigate the effects of an intravenous infusion of BMS-180048, a novel 5HT1-like agonist, on the systemic, pulmonary and coronary circulations in patients undergoing diagnostic cardiac catheterisation. METHODS Ten patients (mean age 55 years (range 41-65)) were studied during diagnostic cardiac catheterisation. The haemodynamic response to an intravenous (i.v.) infusion for 30 min of BMS-180048 (0.56 mg kg(-1) h(-1) for 10 min and 0.39 mg kg(-1) h(-1) for 20 min) was assessed via a 7F Swan Ganz catheter and thermodilution cardiac output system. Quantitative coronary angiography was performed at 10 min intervals. RESULTS BMS-180048 caused a significant increase in systemic arterial systolic blood pressure (rise of 32.5 mmHg, 95% CI 24,44.5) P=0.009), pulmonary artery systolic (12.2 mmHg, 95% CI 6.8,18.5; P=0.009) and diastolic pressures (8.5 mmHg, 95% CI 5.0,13.8; P=0.009), right atrial pressure (4 mmHg, 95% CI 1.5,5.2; P=0.013) and pulmonary capillary wedge pressure (9.5 mmHg 95% CI 5.2,14.0; P=0.09). There was no significant change in cardiac output (0.1 l min(-1), 95% CI -0.17,0.57, P>0.05). Mean coronary artery diameter in the proximal coronary segments decreased by 0.73 mm (95% CI -1.22,-0.15; P=0.03) at 35 min. The corresponding reduction in middle segments was 0.26 mm (95% CI -0.395,-0.08; P=0.02). There was a non-significant trend to constriction in the most distal segments of 0.28 mm (95% CI -0.68,0.015); P=0.06). One patient experienced chest pain with ECG changes suggestive of ischaemia. CONCLUSIONS BMS-180048 displayed a cardiovascular profile similar to that previously reported for sumatriptan. These changes appear to reflect a class effect of these agents.
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Birnie DH, Holme ER, McKay IC, Hood S, McColl KE, Hillis WS. Association between antibodies to heat shock protein 65 and coronary atherosclerosis. Possible mechanism of action of Helicobacter pylori and other bacterial infections in increasing cardiovascular risk. Eur Heart J 1998; 19:387-94. [PMID: 9568442 DOI: 10.1053/euhj.1997.0618] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
INTRODUCTION There is growing evidence that the immune response is involved in atherosclerosis. Antibodies to heat shock protein 60/65 have been shown to be a risk factor for carotid atherosclerosis and been proposed as a diagnostic marker of atherosclerosis. In addition, it has been suggested that the immune response to heat shock protein 60/65 may be a link between exposure to microorganisms and increased cardiovascular risk. AIMS (1) To investigate the association between anti-shock protein 65 titre and coronary atherosclerosis. (2) To assess whether anti-mhsp65 titre is a useful diagnostic marker of atherosclerosis; (3) To examine the influence of Helicobacter pylori infection on anti-heat shock protein 65 titre. METHODS AND RESULTS In the first study we measured anti-heat shock protein 65 titres in 136 consecutive male subjects admitted for routine coronary angiography. Anti-heat shock protein 65 titres correlated with both the severity and extent of coronary atherosclerosis and the relationship remains statistically significant for the presence of atherosclerosis (P = 0.012) after adjustment for possible confounding influences. However the association had insufficient sensitivity to be a useful clinical test. In the second study we recruited 100 patients with confirmed active H. pylori infection and double blindly randomized them to eradication therapy or placebo. Successful eradication of H. pylori led to a significant fall in anti-heat shock protein 65 titres (from a mean of 256.4 AU.ml-1 to 137.5 AU. ml-1. P = 0.033). CONCLUSION These results raise the possibility that exposure to H. pylori and other micro-organisms lead to an increased risk of clinically manifest coronary artery disease by an autoimmune process.
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Swan L, Birnie DH, Hillis WS. The haematological management of patients with cyanotic congenital heart disease. A time for consensus? Eur Heart J 1997; 18:1973-6. [PMID: 9447327 DOI: 10.1093/oxfordjournals.eurheartj.a015208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
AIMS Recurrent venesection of patients with cyanotic congenital heart disease may be detrimental, with an increased risk of cerebrovascular events and symptomatic iron-deficiency. The aim of this study was to determine the venesection policies as practised in hospitals within a U.K. region and to determine if these policies followed current recommendations. METHODS AND RESULTS Fifty-eight consultants (56% response rate) in cardiac specialties completed self-assessment questionnaires regarding the indications for and practice of venesection. Sixty-one percent of those responding were involved directly in the care of patients with cyanotic congenital heart disease and of these clinicians 97% used venesection. Indications for venesection varied, with 51% of those responding using an elevated haemoglobin per se (6.5-21.0 g. dl-1); 78% an elevated haematocrit (0.55-0.75) and 83% symptoms. Desired maintenance haemoglobin and haematocrit levels also varied greatly. Fifty percent of the consultants responding routinely screened their patients for iron deficiency and 23% felt there was no indication for investigating a low mean corpuscular volume. Only 18% of the policies described followed any evidence based principles. CONCLUSIONS The practice of venesecting patients with congenital cyanotic heart disease varies greatly. Policies in many hospitals do not reflect the minimal benefits and considerable risks associated with recurrent venesection.
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Birnie DH, Soutar RL, Robb OJ, Coleman R. Central nervous system relapse of acute lymphoblastic leukaemia identified by magnetic resonance imaging. CLINICAL AND LABORATORY HAEMATOLOGY 1994; 16:205-6. [PMID: 7955932 DOI: 10.1111/j.1365-2257.1994.tb00410.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Abstract
A 38-year-old female presented with moderate anaemia and a leucoerythroblastic blood film. Subsequent investigation showed myelofibrosis in cellular phase. Her haemoglobin quickly and spontaneously recovered with concurrent serological evidence of recent parvovirus B19 infection. This is the first report in the literature of parvovirus causing red cell aplasia in myelofibrosis.
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Mackay S, Bashir AA, Birnie DH. Primordial germ cells and gonadal development in the golden hamster. J Anat 1989; 164:155-63. [PMID: 2606788 PMCID: PMC1256606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We present results of a light and electron microscopical study of the developing hamster gonad. Two main problems have been examined: the source of somatic cells contributed to the developing gonad and the possible presence of nuage in germ cells. Nuage has been previously reported in hamster oocytes at meiosis; its possible presence at earlier stages and in male germ cells, especially meiotic spermatocytes, was investigated. The mesonephros was found to be the major source of somatic cells to the developing gonad, though a contribution from the coelomic epithelium could not be excluded, and interstitial tissue appeared to arise from mesenchymal cells. The presence of nuage associated with nuclear pores and mitochondria in hamster oocytes from Day 15 p.c. onwards has been confirmed. New findings are the association of nuage with intercellular bridges and its presence at earlier stages, including Day 8 p.c., and in male germ cells especially at the time of the entry to meiosis.
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